Fiber-elastomer laminates utilizing an unresinified m-aminophenol primer

ABSTRACT

The strength of the bond obtained between substrates with the aid of phenoplasts, modified phenoplasts and/or epoxy resins, e.g. between fibrous material and an elastomer on vulcanization thereof, is improved by applying, to at least one of the substrates, in addition to a preformed phenoplast, modified preformed phenoplast, and/or preformed epoxy resin, and drying thereon before the assembly thereof with the other substrate, as an adhesion promoter a quantity of m-aminophenol, which may be blended in a phenoplast adhesive, such as an RF dip or an RFL dip, or may be blended in the elastomer latex used for forming an RFL dip. Adhesive/promoter blends and latex/promoter blends for forming the same are also disclosed.

[ 1 Nov. 25, 1975 FIBER-ELASTOMER LAMINATES UTILIZING AN UNRESINIFIEDM-AMINOPHENOL PRIMER [75] Inventors: Oliver W. Burke, Jr., FortLauderdale; Barbara P. Hunt, Pompano Beach, both of Fla.

[73] Assignee: Oliver W. Burke, Jr., Fort Lauderdale, F la' 22 Filed:Jan. 19, 1972 21] Appl. No.: 219,173

[56] References Cited UNITED STATES PATENTS 3,018,207 1/1962 Danielson156/338 X 3,423,230 1/1969 Georges 3,507,689 4/1970 Freytag et a1117/l38.8

3,513,049 5/1970 Marzocchi 156/180 3,537,932 11/1970 Schr0de.....156/310 3,663,268 5/1972 Wilson 117/76 T 3,698,935 10/1972 Yurcick etal. 117/76 T 3,719,724 3/1973 Freeman 260/828 Primary ExaminerCharles E.Van Horn Assistant Examiner-Robert A. Dawson Attorney, Agent, orFirmHa1l & Houghton [57] ABSTRACT The strength of the bond obtainedbetween substrates with the aid of phenoplasts, modified phenoplastsand- /or epoxy resins, e.g. between fibrous material and an elastomer onvulcanization thereof, is improved by applying, to at least one of thesubstrates, in addition to a preformed phenoplast, modified preformedphenoplast, and/or preformed epoxy resin, and drying thereon before theassembly thereof with the other substrate, as an adhesion promoter, aquantity of maminophenol, which may be blended in a phenoplast adhesive,such as an RF dip or an RFL dip, or may be blended in the elastomerlatex used for forming an RFL dip. Adhesive/promoter blends andlatex/promoter blends for forming the same are also disclosed.

27 Claims, No Drawings FIBER-ELASTOMER LAMINATES UTILIZING ANUNRESINIFIED M-AMINOPHENOL PRIMER BACKGROUND OF THE INVENTION '1. Fieldof the Invention This invention pertains to the adhering of substratesto one another, and is particularly but not exclusively applicable tothe adhering of fibrous material to elastomers, more particularly withthe aid of adhesive dips dried on the fibrous material-before assemblyto the elastomer and vulcanization thereof; and to the provision ofadhesive compositions therefor.

2. State of the Prior Art It is known to pretreat various substrates,e.g. fibrous material, with adhesive resorcinol formaldehyde resin (RF)clips, with such RF dips containing a proportion of elastomer latex (RFLdips), and/or with epoxy resin dips, and to' dry the same on the fibrousmaterial before assembling the same with another substrate, e.g. avulcanizable elastomer and curing the same, for the purpose of providinga bond between the substrates, and especially between a vulcanizate andthe fibrous material. Examples of such treatments are disclosed inBritish Patent No. 1,141,807 published Feb. 5, 1969.

BRIEF SUMMARY OF THE INVENTION The present invention aims to promote orincrease the strength of the bond obtained between substrates with theaid of phenoplasts, modified phenoplasts and- /or epoxy resins, e.g.between fibrous material and an elastomer on vulcanization thereof, andthis object is accomplished in accordance with the present invention, byapplying to the substrate, in addition to a preformed phenoplast,modified preformed phenoplast, and/or preformed epoxy resin, and dryingthereon before the assembly thereof with the other substrate, as anadhesion promoter, a quantity of m-aminophenol selected according todefinition hereinafter, which may be blended in a phenoplast adhesive,such as an RF dip or an RFL dip, or may be blended in the elastomerlatex used for forming an RFL dip, and such blends constitute usefulcombinations embraced in the invention.

.. DEFINITIONS In the following detailed description generic andsubgeneric terms are employed according to the following definitions.

1. Rubber or elastorner. The terms rubber, rubber material, elastomer,and elastomer material are used herein to designate elastomericmaterials or rubbery materials including natural rubbers and thesynthetic rubbers which are capable of being cured or vulcanized, as bythe aid of heat and suitable vulcanizing agents. The vulcanizing agents,depending on the particular elastomer, may be of the sulfur type and/orof the free radicaltype, e.g., the peroxide or hydroperoxide type,and/or of other types. Such rubbers include homopolymers and copolymersof conjugated dienes such as polychloroprene, polybutadiene,polyisoprene and copolymers of chloroprene, butadiene and isoprene withvinyl monomers, such as the copolymers of butadiene-styrene,butadiene-acrylonitrile and the like, copolymers of isobutylene andisoprene (the butyl rubbers), copolymers of ethylene and propylene,terpolymers of ethylene, propylene and a non-conjugated 2 diene andother elastomers, e.g. fluorocarbon elastomers, as Viton B or Fluorel.

The term vulcanizable elastomer as used herein designates a rubbercompounded with suitable compounding ingredients including a vulcanizingagent so as to be capable of being cured or vulcanized, as by the aid ofheat. The vulcanizable elastomer may be applied in'any suitable manner,e.g. by calendering, pressing in a mold or deposition from an aqueous orsolvent dispersion.

2. Fibrous Materials. The generic term fibrous material as used hereinis applicable to natural and synthetic fibrous materials, e.g.reinforcing material in the form of filament, yarn, cord, cable, ribbon,and cord fabric unwoven or woven as cloth or canvas to be used inreinforcing rubber articles such as vehicle tires, mechanical rubbergoods such as belts, hose. gaskets, and the like, or as carrier sheetfor adhesive material for interposition between other substrates to bebonded together thereby. Such fibrous materials may consist of cotton,cellulose acetate, organic esters and ethers of cellulose, rayon,polyesters such as ethylene glycol terephthalic acid polyesters(Dacron), the polyvinyls and- /or polyvinylidenes, such as theacrylonitrile polymers (Orlon), polyvinyl chloride and vinylidenechloride polymers (Vinyon), the polyethylenes and other polyolefins, thepolyurethanes (Perluran), the proteins (Caslen), alginates, mineralfibers (fiberglass), polyamides, such as the aliphatic dicarboxylicacid-polyamide reaction products (nylon) and polyvinyl alcohol andcombinations of two or more different fibers e.g. in the same yarn orfabric.

The sub-generic term polyester fiber as used herein and in the art (seeI-I. Ludewig Polyester Fasern Chemie and Technologie, published byAkademie Verlag, Berlin, Germany, 1965 herein incorporated by reference)connotes fibers of linear polymeric polyesters containing the esterlinkage in the main chain. Such fibers include those produced byreacting glycols such as ethylene glycol, propylene glycol,methoxypropylene glycol with carboxylic acids and typical of these isDacron, which is a polyethylene glycol ester of terephthalic acid.

The sub-generic term polyamide fiber as used herein and in the art (seeH. Klare, E. Fritzsche and V. Grobe Synthetische Fasern aus PolyamidenTechnologie and Chemie, published by Akademie Verlag, Berlin, Germany,1963, herein incorporated by reference) designates the syntheticfiber-forming polyamides. Such polyamides are for example those producedby the condensation of a dicarboxylic acid and a diamine, typicallyexemplified by polyhexamethylene adipamide (nylon 66), polyhexamethylenesebacamide (nylon 610), polyhexamethylene dodecanediamide (nylon 612)and polycaproamide (nylon 6).

The sub-generic term glass fiber as used herein applies to continuousglass fibers and discontinuous glass fibers in the form of filaments,strands, yarns, bundles, cords and fabrics formed therefrom and includescrimped and uncrimped fibers, strands, yarns and threads and those whichhave been plied or twisted in multiple groups to form yarns, cords orfabrics, this term includes such glass fibers coated with sizingcompounds or bonding agents or 2,832,754, agents or anchoring agents.Illustrative of such coating agents are organic trivalent chromiumcompounds e.g. methacrylato chromic chlorides or stearato chromicchloride; titanium complexes e.g. titanium tetraesters; silane and 3.siloxanc compounds e.g. the vinyl and allyl trialkoxy silanes. theaminoalkyl and acryloxyalkyl trialkoxy silanes, and other organicsilicone compounds described in U.S. Pat. Nos. 3.484.223, 2.563.288.2.688.006.

2,688,007, 2,723,211, 2,742,378, 2,754,237, 2,776,910, 2,799,598, 2,832,754, 2,930,809, 2,946,701, 2,952,576, 2,974,062, 3,044,982, 3,045,036,3,169,884, 3,207,623, 3,211,684, and

3,459,585, herein incorporated by reference.

3. Epoxy Resins and Epoxy Resin Coatings. The term epoxy resin as usedherein connotes a component for coating substrates, e.g. fibrousmaterials, consisting essentially of organic material having at least 2epoxy groups, i.e.

groups per molecule, or of such material in combination withdiisocyanate material, e.g. l-lylene MP commercially available from theduPont Company. Such epoxy resins may be obtained by reacting forexample epichlorohydrin with a polyhydric phenol such asbis-(4-hydroxyphenyl)-2,2-propane, bis-(hydroxyphenyl) methane. Examplesof such compounds are described in U.S. Pats. Nos. 2,324,483; 2,444,333;2,494,295; 2,500,600; 2,511,913; 2,943,095; 2,872,427; 3,488,314;1,888,358; 2,943,095, and 3,525,703 herein incorporated by reference;and the commercially available epoxy-resins are included hereunder asfor example the ERL resins sold by Union Carbide Corporation under thetrade names ERL 2774, ERL 3794", ERL 2794, ERL 4289, and ERL 2774, TheEpon resins, sold by the Shell Chemical Company, i.e., the 1001, Epon1004, Epon 1007, Epon 1009, Epon 815 and Epon 828; the Araldite resinssold by the Ciba Company, Inc. designated as Araldite 6010, Araldite 502and Araldite 6020; and GenE- poxy Resins sold by General Mills ChemicalDivision, i.e. GenEpoxy 175, 190, 525 and M-l80, and others. The epoxyresin compounds which are insoluble in water may be supplied as a dip inthe form of a solvent solution or an aqueous emulsion or a colloidaldispersion.

4. Dips. The term dip as used herein connotes aqueous or non-aqueoussolutions, suspensions or emulsions which may be applied to substratematerial by dipping, spraying, padding or other suitable procedures,followed by drying.

5. Dried or Drying. The term dried or drying as used herein includesdrying at ambient temperatures and/or elevated temperatures underatmospheric, subatmospheric or elevated pressures, in or oro other, e.g.inert, atmosphere; and at the elevated temperatures is preferablyaccompanied by partial curing of the components by heat and/or with theaid of curative ingredients. dinonylamine,

6. Epoxy Resin Coating. The term epoxy resin coating as used hereinmeans a coating, preferably at least partially cured, of epoxy resin onthe substrate material. For forming an epoxy resin coating, an epoxyresin may be applied to a substrate material as a dip in any suitablemanner, e.g. per se or as a solution in a volatile solvent such asacetone, methyl ethyl ketone, or chloroform or as a water emulsion ordispersion, and preferably is then at least partially cured, preferablywith the aid of a curative of the acid or basic catalyst type. with thelatter being preferred. Typical of such catalysts are those set forth inU.S. Pat. No. 2,872,427, herein incorporated by reference. such asethylene diamine. diethylene triamine, triethylene tetramine,dicyandiamide, melamine, pyridine, cyclohexylamine, benzyldimethylamine,benzylamine, diethylaniline, triethanolamine, piperidine, tetramethylpiperazine, N,N- dibutyll ,3-propane diamine, N,N-diethyl-l ,3-propanediamine, 1,2-diamino-2-methylpropane, 2,7-diamino- 2,6-dimethyloctane,dibutylamine, dioctylamine, diinonylamine, distearylamine, diallylamine,o-tolylnaphthylamine, pyrrolidine, Z-methylpyrrolidine,tetrahydropyridine, 2-methylpiperidine, diaminopyridine,tetraethylpentamine, meta-phenylene diamine, and salts of such amines,and other epoxy resins and catalysts as described in H. Lee and K.Nevilles treatise entitled Handbook of Epoxy Resins, herein incorporatedby reference.

7. Phenoplasts. The term phenoplast or phenoplasts as used hereinconnote those resins which are basic catalyzed reaction products of aphenol and an aldehyde (i.e. the resoles and resitols) and those resinswhich are acid catalyzed reaction products of a phenol and an aldehyde(e.g. the novolacs). Thus the term phenoplasts is used in the acceptedsense as set forth in the treatise entitled Phenoplasts by T. S.Carswell published in 1947 by Interscience Publishers, Inc., New York,N. Y., which treatise is herein incorporated by reference.

Suitable phenols to form the phenoplasts hereof include phenol; dihydricphenols such as resorcinol; substituted phenols such as the alkylatedphenols exemplary of which are m-cresol, o-cresol, m-ethylphenol,m-n-propylphenol, m-isopropylphenol, m-n-hexylphenol, m-n-butyl phenol,m-sec.-butyl phenol, m-tert.- butyl phenol, m-amyl phenol and other likephenols, particularly those wherein the alkyl substituent contains from1 to 9 carbon atoms inclusive; the meta-substituted phenols such asm-aminophenol, resorcinol monoacetate, 1,5-naphthalenediol and the like;metasubstituted alkoxy phenols such as m-methoxy phenol, m-ethoxyphenol, m-n-propoxy phenol and the like, particularly those wherein thealkoxy group contains from 1 to 6 carbon atoms inclusive; as well asthose phenols with similar substituents in the para-position (e.g.p-tert.-butyl phenol) which are suitable for forming novolacs; thepolyhydric polynuclear phenols which consist of two or more phenolsconnected by such groups as methylene, alkylene or sulfone, such asbis(phydroxyphenyl)-methane, 2,2-bis(p-hydroxyphenyl) propane anddihydroxydiphenyl sulfone and the like; and the halogenated phenols andpolynuclear phenols including the meta-halogenated phenols such asmchlorophenol, m-bromophenol and the like.

The monohydric, mononuclear phenols suitable to form the phenoplastsherein can be represented by the following formula:

OH R

wherein R is an alkyl radical containing from 1 to 9 carbon atomsinclusive or an alkoxy radical containing from 1 to 6 carbon atomsinclusive; R is a halogen atom, i.e. chlorine, bromine. iodine orfluorine; and n is an integer having a value of O to l inclusive.

Suitable aldehydes to form the phenoplasts hereof include formaldehydein any of its available forms, (i.e., formalin, paraformaldehyde andtrioxane), furfural, glyoxal, acrolein and the like.

8. Novolac Resins. The terms novolac or novolac resin are used herein inthe accepted sense employed in T. S. Carswells treatise Phenoplastsreferred to above. Thus, the novolac resins are well known phenoplastproducts which are usually acid-catalyzed phenol aldehyde condensates,and which are prepared by condensing a phenol and an aldehyde in thepresence of an acid such as oxalic acid, sulfuric acid, hydrochloricacid and the like or in the presence of a metal salt of an acid such aszinc acetate, wherein the phenol is present in the reaction mixture inmore than stoichiometric amounts. Novolac resins can be converted to theinfusible state by the addition thereto of a cross-linking agent such asa methylene generating agent such as hexamethylenetetramine.

The following commercial resins used in certain of the exampleshereinafter are reported to be novolac resins:

a. The trademark product Durex 12686, a cashew nut oil modified phenolicnovolac resin (used in Table XX, examples 75-78);

b. the trademark product Durex 22193, a thermoplastic resin cured withthe aid of a polyamide resin (used in Examples 83-85, Table XXII);

c. the trademark product Penacolite R-2170, a 75% aqueous solution of aresorcinol-formaldehyde condensation product requiring the addition of amethylene donor to become thermo-setting (used in Examples 79-82, TableXXI).

9. Methylene donor. The term methylene donor as used herein includesthose compounds which provide methylene linkages in reacting withsoluble or plastic or heat softenable phenoplasts, e.g. A-stage resins(resoles) or B-stage resins (resitols), or novolacs to form cross-linkedinsoluble, infusable resins, e.g. C-stage resins (resites). Suchmethylene donor material include hexamethylenetetramine (hexa), as wellas formaldehyde, which term includes formaldehyde and various polymericforms thereof such as paraformaldehyde, trioxane and the like.

10. RF Resin. The term resorcinol formaldehyde resin or RF resin as usedby the trade and herein means an acid or basic catalyzed phenolic resinwhich consists essentially of the reaction product of a substitutedphenol and an aldehyde, heat hardening per se or with the aid of amethylene donor and/or metal oxide. Suitable substituted phenols includephenols having substituents selected from the groups consisting of-OI-I, NI-I or --OCOCH groups, such as resorcinol, m-aminophenol,resorcinol monoacetate, 1,5- naphthalenediol and other typical phenolsemployed to form phenolic type adhesives and combinations of suchphenols. Suitable aldehydes for the reaction include furfural, acrolein,glyoxal, and especially formaldehyde which may be employed as formalin(37% by weight formaldehyde gas in water), and combinations of two ormore thereof. The resin forming reaction is preferably carried out inwater with the aid of an alkali metal hydroxide or carbonate such assodium hydroxide or sodium carbonate; or with aqueous ammonia; or with awater soluble or dispersible amine such as monoethanolamine,diethanolamine, triethanolamine, and/or the unsaturated amines such asdiallylamine, triallylamine,

6 and the vinylamine monomers, e.g. t-butylaminoethyl methacrylate anddimethylaminoethyl methacrylate. The RF resin may be applied to thefibrous material or pretreated fibrous material in the form of a dip anddried thereon as above described.

1 l. Phenoplasts modified with Modifying Polymer. In connection withadhesive compositions herein, the terms phenoplasts modified withmodifying polymers or modified phenoplasts are used to refer tophenoplasts plus modifying polymers, e.g. synthetic rubbers andthermoplastic resins which may be employed to improve flexibility andadhesion to particular substrates, including but not limited to naturalrubber; polybutadiene; polyisoprene; polychloroprene;butadiene/acrylonitrile, butadiene/vinyl pyridene,butadiene/styrene/vinyl pyridene, butadiene/styrene,isobutylene/isoprene, and other hydrocarbon diene/- vinylideneinterpolymers; ethylene/propylene and other alph olefin polymers andinterpolymers; the foregoing polymers and interpolymers provided withcarboxyl groups; and combinations of two or more of the foregoing. Thusthe modified phenoplasts include compositions comprising phenoplasts andmodifying resins selected from the class consisting of the members ofthe following groups:

1. polychloroprene (Neoprene elastomer);

2. butadiene-acryonitrile copolymers (nitrile elastomers);

3. butadiene-styrene copolymers;

4. thermosetting or curing epoxy resins;

5. thermoplastic vinylidene resins, including vinyl resins, e.g.polyvinylformal resins;

6. thermoplastic polyamide resins;

7. other known polymeric materials suitable as modifiers forphenoplasts;

8. combinations of two or more of the foregoing polymeric modifiers. SeeAdhesives Guide by Joyce I-Iurd, B.S.I.R.A. Research Report M-39, 1959,The Cable Printing & Publishing Co., Ltd., London, herein incorporatedby reference.

l2. Adhesive Composition. The term adhesive composition as used hereinincludes phenoplasts with and without modifying polymer dispersed in aliquid dispersing medium, or carried by a carrier sheet. In the liquiddispersion form it is exemplified by the resorcinol formaldehyde (RF)dips, and the resorcinol formaldehyde elastomer latex (RF L) dips. Theadhesive composition is applied as a liquid dispersion in a liquiddispersing medium and said liquid is preferably a volatile organicliquid such as an aliphatic or aromatic hydrocarbon, an alcohol such asethanol, propanol, isopropa- 1101 or the like, or a ketone such asacetone, methylethyl ketone, diethyl ketone or the like and mostpreferably the liquid dispersing medium is aqueous. When the adhesivecomposition is aqueously dispersed then a cationic or anionic and/ornon-ionic dispersing agent may be employed. The liquid dispersedadhesive phenoplast (modified or unmodified) compositions, in uncured orpartially cured form may be applied to a substrate, which may beselected from the class consisting of plastic film, woven fabricsnon-woven fiber sheeting, and metal foil, and may be dried thereon forapplication as a sheet to be interposed between substrates to be joinedby curing thereof. The liquid dispersed epoxy resin adhesives may besimilarly applied except that they must be at least partially curedbefore being contacted with the m-aminophenol promoter.

13. RFL Dips. The RF resin is preferably employed with an elastomerlatex and such combination is referred to by the trade and herein as RFLor as an RFL clip. The elastomer latices employable in such RFlcombinations include natural Hevea latex, natural rubber latices graftedwith vinyl compounds such as methyl methacrylate, vinylpyridine, etc.,and various synthetic rubber latices such as homopolymer latex of a C toC conjugated diene compound, and copolymer latices obtained by thecopolymerization of a C, to C conjugated diene with one or more vinylmonomers such as styrene, vinylpyridine, acrylonitrile, acrylic acid,methacrylic acid, alkyl acrylates and alkyl methacrylates and the like,e.g. styrene-butadiene copolymer latex, polybutadiene latex,polyisoprene latex, polychloroprene latex, isoprene-isobutylenecopolymer latex, butadiene-acrylonitrile copolymer latex,butadiene-methacrylic acid copolymer latex, butadiene-styrene-acrylicacid copolymer latex, and a preferred elastomer latex is a vinylpyridinelatex, usually used in combination with another elastomer latex, forexample as described in U.S. Pat. No. 2,561,215, herein incorporated byreference, wherein the vinylpyridine latex comprises an aqueousdispersion of a copolymer of 50 to 95 percent by weight of a conjugateddiolefin having 4 to 6 carbon atoms, 5 to 40 percent of a vinylpyridine,and -40 percent of a styrene, and suitable vinylpyridines are2-vinylpyridine, 2-methyl-5-vinylpyridine and -ethyl-2-vinylpyridine.Such a vinylpyridine latex is commercially available as Gen-Tao, atrademark product of General Tire and Rubber Co., which is reported tobe a vinylpyridine latex consisting of a copolymer of 70% butadiene, 15%styrene and 15% 2- vinylpyridine having a total solids content of around40 percent. It is usually desirable to blend the vinylpyridine latexwith an SBR rubber latex as for example a blend of 70 to 80% of an SBRrubber latex and 20 to 30% by weight of the vinylpyridine latex. Theelastomer latex component of an RFL dip may be added to a preformed RFresin as an aqueous dispersion, or the RF resin may be prepared in thepresence of the elastomer latex. The RFL dip may be applied to thefibrous material or pretreated fibrous material and be dried thereon asabove described.

14. Adhesion Promoter. The adhesion promoter of the present invention ism-aminophenol as hereinafter defined, applied in conjunction with anadhesive used to bond together composite structures and/or substratesand said adhesive preferably being a phenoplast resin with or withoutmodifying polymer. In particular applications such adhesive promoter isapplied to fibrous materials in a manner to improve the bond strengthdeveloped between the fibrous material and an elastomer material by adried epoxy resin and/or RF or RFL resin composition.

15. M-aminphenol. The term m-aminophenol as used in the presentinvention connotes m-aminphenol (i.e. 3-aminophenol or m-hydroxyaniline)and its salts with acids having an appreciable water solubility, i. e.including the water soluble acids which include water soluble mineralacids and water soluble organic acids, and these unresinified materialsare distinguished from and do not include aldehyde reaction productspreformed therefrom which are RF resins under definition 10) above. Thewater soluble mineral acids comprise sulfuric acid, hydrochloric acid,and the like. The water soluble organic acids comprise, but are notlimited to, the water soluble, aliphatic monocarboxylic acids, e.g. thealkenoic acids of l to 3 carbon atoms (formic, acetic, and propanoic)and the water soluble, hydroxylalkanoic acids such as hydroxyaceticacid, 2-hydroxypropanoic acid, 3-hydroxypropanoic acid, thehydroxybutanoic acids, 2,3-dihydroxypropanoic acid, and citric, oxalic,malonic, maleic, fumaric, acrylic, methacrylic acids and the like. Themaminophenol may be applied to a substrate prior to, concurrently with,or subsequently to the application thereto of the preformed phenoplast,and the material may be dried thereon sequentially or concurrently toprepare the composition.

l6. Substrate. The term substrate as used herein refers to any solidmaterial, e.g. fibrous material, sheet material, structural elements ofwood, metal and/or plastic, including but not limited to, the fibrous orsheet material as set out under (2) and (12) above to which the adhesivecompositions of the present invention may be applied and dried inuncured condition, and which may become a part of a composite structurewhen the adhesive composition is cured.

17. Composite structure. The term composite structure as used hereinconnotes any structure comprising a plurality of substrate elements ormembers assembled with adhesive material according to the invention.

Detailed Description In a first aspect of the method category of thisinvention, in the formation of a bond by vulcanizing a vulcanizableelastomer to a fibrous material with the aid of an ahdesive dip ofresorcinol formaldehyde resin with or without a quantity of elastomerlatex dried on the fibrous material before assembly with the elastomerand vulcanization thereof, which fibrous material may also have beentreated with a clip of epoxy resin and dried, to improve the bond thereis also applied to the fibrous material, and dried thereon before suchassembly, a dip of m-aminophenol. The ratios of the coating componentson the fibrous material applied as individual or combined componentclips are preferably as follows: epoxy resin (dry basis) 0-2 parts byweight; resorcinol formaldehyde resin (dry basis) 1 part by weight;elastomer latex (dry basis) 0-15 parts by weight; m-aminophenol (drybasis) 0.1 to 4 parts by weight. In the single or combined componentdips a quantity of water or volatile solvent is employed in suchproportion that the dry solids content of the dip is preferably in therange of 0.1% to 10% by weight.

In particular procedural embodiments of the invention the adhesive dipof resorcinol-formaldehyde resin and the m-aminophenol dip may be atleast in part applied to the fibrous material and dried thereonconcurrently; or the adhesive dip of resorcinol formaldehyde resin andthe m-aminophenol dip may be at least in part applied to the fibrousmaterial and dried thereon sequentially; or at least a part of them-aminophenol dip may be applied to and dried on the fibrous materialafter the drying thereon of the adhesive dip of resorcinol formaldehyderesin.

In certain embodiments of the invention the fibrous material is selectedfrom the class of fibrous materials suitable for use as tire cordconsisting of the polyamide fibers, the polyester fibers and the glassfibers, with or without said fibrous material having been pre-treatedwith an epoxy resin dip and dried.

In an embodiment of its product aspect the invention provides acomposite structure consisting essentially of a vulcanizable elastomervulcanizate bonded to a fibrous material with the aid of an adhesivefrom a resorcinol formaldehyde resin dip with or without a portion ofelastomer latex, particularly characterized in that the bonding of saidadhesive is augmented by m-amiphenol applied to and dried on the fibrousmaterial prior to its assembly with the elastomer and vulcanizationthereof; and in another embodiment the invention provides acompositestructure consisting essentially of a vulcanizable elastomervulcanizate bonded to a fibrous material with the aid of epoxy resinadhesive and an adhesive from a resorcinolformaldehyde resin dip with orwithout a portion of elastomer latex, particularly characterized in thatthe bonding of said adhesives is augmented by m-aminopheno] applied toand dried on the fibrous material prior to its assembly with theelastomer and vulcanization thereof.

Also as useful subcombinations the invention provides:

A. an improved adhesive composition for bonding substrates to oneanother, said adhesive composition being a. liquid dispersioncomprising, by weight, the combination of:

a. to 250 parts of liquid dispersing medium,

b. parts of phenoplast material selected from the members of the classconsisting of group (I) the heat curable phenoplasts containing methylolgroups; group (II) the mixtures of 1) novolac phenoplasts substantiallyfree from methylol groups with (2) at least sufficient methylene donormaterial to enable heat curing of the same; group (III) mixtures of (l)phenoplasts which complex with metal oxides with (2) at least sufficientmaterial selected from the oxides and hydroxides of the metals calcium,magnesium and zinc, to complex with the phenoplast; and (4) heat curablecombinations of the foregoing,

c. 0 to 150 parts of modifying polymer, and

d. 0 to 30 parts of material selected from the oxides and hydroxides ofthe metals calcium, magnesium, and zinc,

the said composition being improved in that it contains in thecombination e. l to 40 parts by weight of m-aminophenol.

B. a composite structure comprising a substrate having such improvedadhesive composition applied thereto; and especially one in which the soapplied composition has been substantially freed of said liquiddispersing medium.

C. an adhesive material for bonding substrates to one another, saidadhesive material consisting essentially of a. a vehicle, and carriedthereby, dry basis by weight,

a mixture of b. 10 parts of heat curable phenoplast,

c. 0 to 150 parts of elastomer,

d. 0 to 50 parts of inorganic material selected from the oxides andhydroxides of the metals calcium, magnesium and zinc,

e. 0 to 40 parts of donor material and f. 1 to 40 parts ofm-aminophenol; and especially such an adhesive material wherein saidvehicle is selected from the class consisting of volatile liquid andnon-volatile solid carriers.

D. An aqueous adhesive composition comprising a mixture, dispersed inthe aqueous phase, dry basis by weight, of l a. 1 part phenoplast resin,

b. from 0 to 2 parts epoxy resin,

c. from 0 to parts elastomer latex, and

i in preparing modified phenoplast adhesive compositions which consistessentially, dry basis by weight, of

a. 15 parts elastomer latex, and

b. from 0.1 to 4.0 parts m-aminophenol; and especially such an improvedcomposition in which at least 0.5 parts of the elastomer latex is avinyl-pyridine latex, a polychloroprene latex, a butadieneacrylonitrilelatex, a latex of polychloroprene having carboxyl substituents, or alatex of butadiene-acrylonitrile polymer having carboxyl substituents,or a combination of two or more such latices.

F. A composition for use in forming phenoplast adhesive compositionswhich consists essentially of a mixture of hexamethylemetetramine andm-aminophenol in the proportions by weight of from about 1 to 40 toabout 40 to 1.

In more detail in certain embodiments of this invention one of thesubstrates, e.g. a fibrous material is bonded to the other substrate,e.g. a compounded elastomer with the aid of an adhesive system in whichthe adhesives are selected from the class of adhesives resins consistingof the epoxy resins, RF resins, RFL resins and combinations of suchresins; and with m-aminophenol as adhesion promoter; and the exampleshereinafter typify various embodiments of the invention. Among theseembodiments are those employing the maminophenol as an adhesion promoterin the following sequences and combinations:

i. fibrous material epoxy resin m-aminophenol" elastomer compound ii.fibrous material epoxy resin m-aminophenol RF resin or RFL resinelastomer compound iii. fibrous material epoxy resin m-aminophenol RFresin or RFL resin m-aminophenol elastomer compound iv. fibrous materialepoxy resin m-aminophenol RF resin or RFL resin plus m-aminophenolelastomer compound v. fibrous material epoxy resin RF resin or RFL resinm-aminophenol elastomer compound vi. fibrous material epoxy resin RFresin or RFL resin plus m-aminophenol elastomer compound vii. fibrousmaterial m-aminophenol RF resin or RFL resin elastomer compound viii.fibrous material RF resin or RFL resin maminophenol elastomer compoundix. fibrous material RF resin or RFL resin plus maminophenol elastomercompound x. fibrous material epoxy resin plus RF resin or RFL resinm-aminophenol" elastomer compound l. The epoxy resin preferably pluscatalyst as a volatile organic solvent solution or as an aqueousemulsion is applied to the fibrous material and preferably at leastpartially cured thereon. 2. The m-aminophenol is applied to the fibrousmaterial from a volatile organic solvent solution or from an aqueoussolution and dried with or without a heat treatment step. 3. The RFresin or RFL resin is applied as an aqueous dispersion to the fibrousmaterial (with or without epoxy resin coating) and dried. 4. Them-aminophenol is applied from a volatile organic solvent solu' tion orfrom an aqueous solution to the treated fibrous material.

5. The RF or RFL resin as aqueous dispersion with m-aminophenol isapplied to the fabric material and dried; and the rcsorcinol formaldehyde resin is prepared in aqueous dispersion with the aid of preferablya basic catalyst, e.g. sodium hydroxide, ammonia or the amines; and ifelastomer latex is employed it can be added prior, during or afterformation of the RF resin to form the RFL resin; however, them-aminophenol to act as a adhesion promotor must be added after the RFresin or RFL resin has formed or may be added with the latex when it isadded to the preformed RF resin, in which case a preformed mixture asset out under (E) above is an especially useful subcombination. 6. Theelastomer compound is contacted or bonded to the adhesive treatedfibrous material preferably with the aid of pressure as by pressing in amold or by calendaring or by other contacting means and the combinationis cured. 7. In this system a dip is prepared by combining the followingcomponents:

a. Epoxy resin (as aqueous dispersion) b. RF resin or RFL resin (asaqueous dispersion) and applied to the fibrous material and dried(drying includes without or with heating at elevated temperature e.g. 30minutes at 165C.). Then a dip of m aminophenol is applied and dried.

The modes of realizing and embodying each of the foregoing aspects andprocedures of the invention are set forth in detail in the examples1-62, which are to be taken as illustrative and not restrictive of theinvention, the scope of which is more particularly pointed out in theappended claims.

EXAMPLES l-62 The following Examples and their tabulations demonstrateapplicants discovery of the effect of m-aminophenol as an adhesivepromoter in improving the bond strength between fibrous material andelastomer material when bonded with an epoxy resin and/or with arescorcinol formaldehyde resin with or without elastomer latex, in eachof the above noted aspects, as indicated in connection with therespective groups or tables thereof.

Examples 1-8 (Table I) This group of Examples comprises working examplesbearing B numbers and comparative or control Examples bearing A numbers,the B numbered examples employing the invention; and the last twocolumns showing by comparison with the A Examples the improvementseffected thereby. In these Examples polyester fabricsare prepared foradhering to polychloroprene by coating a fabric such as Dacron with anemulsion of epoxy resin and a selected curative, then letting thecoating on the fibrous dry and curing it for 30 minutes at 163C. In theB Examples such epoxy resin coated Dacron is then after-treated with anaqueous solution of m-aminophenol, allowed to dry, and laminated to acompounded Neoprene rubber sheet and cured for 45 minutes at 165C., anda high tensile strength bond occurs between the Dacron and the Neoprene.If the m-aminophenol step is omitted, as in the control or A Examples,the peel strength of the laminate is considerably lowered.

Examples 1 through 8 set forth in Table I also illustrate that theadvantages of the invention are not dependent on the type of curativeused for curing the epoxy resin, or on the level of curative employed.For this purpose four different amine curatives each at a high and lowlevel were added to the aqueous emulsion of the epoxy resin ofdiglycidyl ether of bisphenol A.

When reference is made in the Tables to the unaged peel strength thismeans the peel strength determined on a sample which has not beensubjected to the aging effect of prolonged immersion in hot water, e.g.14 days, prior to the peel strength test.

Preparation of Epoxy Resin Emulsions In Table I-A recipe I is set forthfor the preparation of epoxy resin emulsions as follows: the epoxy resinand a small amount of non-ionic emulsifier polyoxyethylene sorbitanmonosteareate" were first dissolved in chloroform, the weight proportionbeing 20 parts epoxy resin, 2 parts non-ionic emulsifier, and 78 partschloroform. These were mixed together for about 2 minutes in a blender,and then agitation'was continued at high speed while an aqueous solutionof anionic emulsifer was added very slowly. This solution consisted of 2parts lauryl alcohol sulfate and 98 parts water, and then 200 partswater. Agitation was continued for another 5 minutes and then theemulsion was removed from the blender and diluted with water as desired,usually to provide a 5% epoxy resin solids emulsion.

1. Tween 60, a Trademark designation of the Atlas Chemical Industries.

2. Dupon ME, a Trademark designation of E. I. du Pont de Nemours and Co.Inc.

When a water-soluble curative for the epoxy resin was to be included inthe emulsion it was added, dissolved in water for dilution. When achloroform-soluble curative such as methylene-bis-orthochloroaniline wasto be used, it was added dissolved in a small amount of chloroform, andadded to the epoxy resinchloroform solution at the beginning of theemulsification process, with the weight of curative and chloroform usedto dissolve it being substracted from the 78 parts chloroform otherwiseused to dissolve the epoxy resin.

Sixteen batches of epoxy emulsion dip were prepared according to recipeI Table I-A employing as epoxy resin a diglycidyl ether or bisphenol Ahaving an epoxy equivalent of about 200 and viscosity about 20,000 cps.In Table I is set forth the amount of curative added to each of thesebatches e.g. in Example 1A and IE to the emulsion containing 20 grams ofepoxy resin was added 0.68 grams of tetraethylenepentamine.

The amine curing agents were added to the epoxy emulsions from 5%solutions of the particular amines in water or a mixture of equal partsby weight of water and isopropanol. All the epoxy emulsion examples withcuratives were further diluted with water so as to contain 1% epoxyresin content by weight.

Two proportions each of four different amine compounds were used. Thesecompounds included tetracthylenepentamine, which has both a primary andsecondary amine groups; diethanolamine, a secondary amine; andpiperidine and dimethylaminomethylphenol (DMP-IO, Rohm & Haas Co.) whichare tertiary amines. The proportions of these amines as parts by weightper hundres epoxy resin is shown in Table I and was equal to 25% and100% of proportions com monly used in curing epoxy resins except in thecase of tetraethylenepentamine which was used in amounts equal to 25%and of the proportions commonly used in curing epoxy resins.

Pieces of polyethylene terephthalate, (Dacron, E. I. Du Pont de Nemoursand Co. Inc.) were soaked for about a minute in various dips as setforth under fabric treatment A, Table I, and then were dried overnightat ambient temperature, followed by heating for 30 minutes at C. to atleast partially cure the epoxy resin. In the Tables an X designates thatthe captioned material or treatment was used; a dash that it was not.

13 Samples of each of these treated fabrics were re served for controlor comparative testing while other portions were further treated bydipping into 0.5% aqueous solutions of m-aminophenol as set forth under14 the speed of separation of the jaws of the testing machine (ScottTester Model LSORR) was 2 inches per minute. One ply of the specimen wasinserted in each clamp and then as the peeling of the specimenprogfabric treatment B, Table I and then dried for 16 hours 5 ressed,the peel strength in pounds was read directly at ambient temperature,after which they were again from the dial of the machine. After valueswhich were cured for 30 minutes at 165C. thought to be unnaturally highdue to twisting of the The treated pieces of Dacron and the controlsthus specimen or tearing of the elastomer etc., had been dispreparedwere then each press-laminated with a small carded, the five highestvalues remaining were aversheet of uncured polychloroprene compoundedacaged and the average recorded as initial peel strength in cording torecipe A, Table IV to provide laminates. pounds per inch width whichvalues are set forth in Table I and the other tables hereafter. Methodof Testmg the Strength of Fabnc'ElaStOmer Specimens to be tested forwater-resistance of the ad- V Bonds hesive bond were then immersed in an82C. water bath Laminates of treated fabrics and elastomer cornfor 2weeks, after which they were removed, temperapounds were formed bysandwiching a small rectangutures equilibrated for 30-9O minutes inwater at ambilar piece of compound (which had been sheeted out on enttemperature and then tested for peel strength. The a rubber mill to lessthan an eighth of an inch in thickdata obtained in these tests ispresented in Table I, and ness) between two rectangular pieces oftreated fabric it may be seen that in every case a secondary treatmentabout 3 by 4 inches in size and the laminates pressed of the fabric witha m-aminophenol dip resulted in subtogether in a laboratory Carver Pressfor 1 minute at stantially better peel strength than was obtained withabout 100C. and 460 psi. The applied pressure forces Dacron treated onlywith epoxy emulsions containing the elastomer compound into the weave ofthe fabric, amine curative.

TABLE 1 ADHESION OF POLYESTER FABRIC TO POLYCHLOROPRENE Comparison ofPolyester Fabric Coated with Epoxy Resin Cured with Various Curatives,With and without After-Treatment with m-Aminophenol Fabric* Treatment AFabric* Treatment B Bonded to Polychloroprene Diglycidyl ether of EpoxyResin Coating Aqueous After-treatment and Tested Bisphenol A (Dry)(Cure) m-AP Dip (Dry) (Cure) (Peel Strength)(lb./1"wid.)

Example Epoxy Emulsion Dip (16 hrs./ min./ (0.5 wt. (16 hrs./ (30 min./(Aged 14 days No. (Curative for dip) 27C.) 165C.) m-amino- 27C.) 165C.)Unaged in 82 water) 1 (a) 3.4 phr TEPA X X l2 6 l (b) 3.4 phr TEPA X X XX X 37 16 2 (a) 20.0 phr TEPA X X 16 9 2 (b) 20.0 phr TEPA X X X X X 3920 3 (a) 3.0 phr DEA X X 9 3 3 (b) 3.0 phr DEA X X X X X 34 14 4 (a) 12phr DEA" X X 9.5 3 4(b) 12 phr DEA X X X X X 41 16 5 (a) 2.5 phr DMP-IOX X 7 5 5 (b) 2.5 phr DMP-lO X X X X X 38 13 6 (a) 10 phr DMP-lO X X l13 6 (b) 10 phr DMP-lO X X X X X 21 7 (a) 1.4 phr piperidine X X 7 3 7(b) 1.4 phr piperidine X X X X X 35 16 8 (a) 5.6 phr piperidine X X 7.53 8 (b) 5.6 phr piperidine X X X X X 32 8 Dacron "The epoxy resin is atrademark product Araldite 6020, Ciba Products Co. and has an epoxyequivalent of 196-208 and a vis. of 16900-20900 cps, and is employed asan aqueous emulsion containing 1.0% epoxy resin solids and curvativeadded to emulsion in phr basis. see Recipe 1, Table I-A.

J I .1 an a,

insuring good contact between fabric and elastomer.

The laminates were then pre-heated 20 minutes at 115C. followed bycuring them (usually for minutes) at 165C. in an air oven) withoutweights upon them. After curing and cooling of the laminates, specimens1 inch wide were cut therefrom for peel test purposes.

The test for peel strength requires the plies at one end of the specimento be separated for insertion into the jaws of the testing machine. Tofacilitate this separation, a masking strip of cellophane tape wasplaced across one end of one of the pieces of fabric before assembly andlamination with the elastomer compound so that the elastomer at that endadhered to only one sheet of fabric.

Peel strength was determined according to Method 5950 of FederalSpecification CCT-191B, except that of Rohm & Haas Cov TABLEI-A-continued PREPARATION OF EPOXY EMULSION Recipe (S /1 epoxy dip) DIPI (grams) Type phr* Examples 9 through 12 (Table II) Two portions ofemulsion containing 5% by weight of an epoxy resin (Araldite 6020, CibaProducts Co.) were prepared according to recipe I, Table I-A and dilutedwith water to 1000 grams containing 2% by weight resin and designated Iand II.

To I was added 108 grams of a 2.5% aqueous solution of m-aminophenol ascurative for the epoxy resin, i.e. 13.5 parts per hundred of epoxy resinsolids. Then enough water was added to dilute the emulsion to 2000 gramsand reduce the epoxy solids content to 1% by weight.

To 11 was added 216 grams of the 2.5% aqueous solution of m-aminophenolas curative for the epoxy resin, equal to 27 parts per hundred of epoxyresin solids. Then enough water was added to dilute that emulsion to2000 grams and reduce its epoxy solids content to 1% by weight.

A piece of Dacron fabric was dipped into emulsion I containing 13.5 phr(parts per hundred of resin by weight) of m-aminophenol and divided intofour pieces and treated as follows: in example 9A a piece of the treatedfabric was dried 17 hours at 27C. and cured 30 minutes at 165C.; inexample 98 a piece of the fabric was treated in the same manner at 9Aplus being dipped in an 0.5% by weight aqueous solution of maminophenoldried 17 hours at 27C. and cured 30 16 aqueous solution of m-aminophenoldried 30 minutes at 90C. and cured 30 minutes at 165C.

Another piece of Dacron fabric was dipped into emulsion II containing 27phr of m-aminophenol and divided into four pieces and treated asfollows: in example 10A a piece of fabric was treated exactly like 9A;in example 10B a piece of the fabric was treated exactly like 9B; inexample 12A a piece of the fabric was treated exactly like 1 1A; and inexample 12B a piece of the fabric was treated exactly like 1 1B.

The data given in Table II shows that when Dacron is treated with anepoxy resin cured with m-aminophenol and bonded to polychloroprene thatstrength of such bond can be improved by further treating the driedepoxy coated Dacron by dipping in an aqueous solution of m-aminophenoland drying the resulting coating.

The eight treated fabrics prepared thus were then press-laminated topolychloroprene compound A, Table IV, in a Carver Laboratory press at100C. and 460 psi for one minute, and the laminates were heated minutesat l 15C. and then heated 60 minutes in an air oven at 165C.

The strength of the fabric-elastomer bond was determined as describedfor examples 1 through 8 heretofore and the data presented in Table II.This data shows that the peel strength of Dacron-neoprene laminates wassubstantially improved when Dacron fabric already treated with epoxyresin and m-aminophenol combined in an emulsion as curative therefor andat least partially cured, was given a second treatment of a 0.5 aqueoussolution of m-aminophenol after such partial curing followed by dryingand heat-treatment thereof. Whether the laminate after-treatment I or IIwas dried 17 hours at ambient temperature or 30 minutes at 90C. seemedto have little effect on the peel strength of the laminate except forexamples 1 1A and 1 1B which had lower values than the correspondingexamples 9A and 9B. All the B examples which were after-treated withm-aminophenol exhibited bonds with higher peel strength than the controlor comparative A examples prepared without such after-treatment.

TABLE II ADI-IESION OF POLYESTER FABRIC TO POLYCHLOROPRENE Comparison ofPolyester Fabric Coated with Epoxy Resin Cured with m-Aminophcnol Withand without After-Treatment with m-Aminophenol Fabric* Treatment AFabric* Treatment B Bonded to Polychloroprene Diglycidyl ether of EpoxyResin Coating m-Amino- After-Treatment and Tested Bisphenol A (Cure)phenol (Heat) Peel Strength, lb./1" wid. Example Epoxy Emulsion Dip (30min./ (0.5 wt. (30 min./ (Unaged) (No.) (Curative for dip) (Drying)165C.) in water) (Dry) 165C.)

(X) (X) (X) (X) 9 (A) 13.5 phr m-aminophenol 17 hrs/27C. X 32 9 (B) 13.5phr m-aminophenol l7 hrs/27C. X X 17 hrs/27C. X 48 10 (A) 27 phrm-aminophenol l7 hrs/27C. X 29 10 (B) 27 phr m-aminophenol l7 hrs/27C. XX 17 hrs/27C. X 35 11 (A) 13.5 phr m-aminophenol 30 min/90C. X 18 11 (B)13.5 phr m-aminophenol 30 min./90C. X X 30 min/90C. X 36 12 (A) 27 phrm-aminophenol- 30 min./90C. X

12 (B) 27 phr m-aminophenol 3O min./90C. X X 30 min/90C. X

Dacron "The epoxy resin is a trademark product Araldite 6020, CibaProducts Co. and is employed as an aqueous cmulsion containing 1.0%epoxy resin solids and curalive added to emulsion in phr basis, seeRecipe I. Table 1A. phr parts by weight per hundred parts by weight ofepoxy resin Compounding recipe (A), Table IV,

Examples 13 through 19 (Table III) Examples 13 through 19, Table III,present a comparison of 7 epoxy resins which were employed as 1% resinsolids solutions in chloroform with all but one having 10 phr of thecurative methylene-bis-orthochloroani- 17 line. The solution of thecycloaliphatic epoxy resin of example 16(a) was an exception in thatthis resin was dissolved in isopropanol and the 1% resin solids solutioncontained 10 phr tetraethylenepentamine as resin Examples 20 through 27(Table III-A) Eight epoxy resins were compared in experiments in whichDacron polyester fabric (see examples 2O curative. 5 through 27 of TableIII-A), was first soaked for about a Pieces of the polyester fabricDacron were treated minute. in a 0.5% solution of the particular resinin with these solutions by immersion and gentle agitation chloroform ortrichlorethylene, then was dried at about for about a minute, then weredried seventeen hours at 27C. until the solvent had evaporated. Thefabric was 27C. followed by curing 30 minutes at 165C. The fabthen curedfor 1 hour in a 165C. air oven. rics were then each divided into twoportions, one of Each of the epoxy-treated fabrics was then dipped whichwas cured an additional 30 minutes while the into a 0.5% aqueoussolution of m-aminophenol, after other was after-treated in a 0.5%solution of m-aminowhich it was dried at about 27C. for about 16 hoursphenol and dried 16 hours at 27C. then was heated 30 followed by heatingfor 30 minutes at 165C. minutes at 163C. The adhesion of these treatedfabrics to polychloro- Test specimens of each of the treated fabricswere prene was evaluated by preparing test laminates of the laminated toa polychloroprene compound prepared fabrics with a polychloroprenecompound (see comaccording to compound A, Table IV and tested by thepound A, Table IV) as described above, and determinmethod described forexamples 1 through 8 above. ing the peel strength of specimens cut fromthe cured A description of the various epoxy resins and the peellaminates. The data obtained from these tests is prestest data obtainedfor the treated polyester fabrics are ented in Table III-A. This tableteaches it is unnecesprese'nted in Table III. It is noted that when thepolyessary to coat the polyester fabric with an epoxy resin ter fabricis treated with m-aminophenol in treatment which contains curative asthe epoxy resin can be cured step 8 the peel strength in most instancesis more than or partially cured to the fabric with heat alone anddoubled. without curative being present with the epoxy resin.

TABLE III ADHESION OF POLYESTER FABRIC TO POLYCHLOROPRENE Comparison ofPolyester Fabric Coated with Various Epoxy Resins Cured with TypicalCurative, With and without After-Treatment with rn-Aminophenol FabricTreatment A Fabric Treatment B Bonded to Polychloroprene Epoxy ResinCoating Resin Cure m-Aminophenol Dry Heat Compound and Tested Ex. 0.5%Epoxy in chloroform plus 10 phr of min./ (0.5% wt. (16 hrs./ (30 min./Peel StrengthJb/l wid. No. Curative methylene-bis-orthchloroaniline**163C.) in water) 27C.) 163C.) (unaged) 13 (A) Diglycidyl ether ofbisphenol A X X l1 13 (B) X X X X 38 14 (A) Polyglycidyl ether ofphenol-formaldehyde resin X X 18 14 (B) X X X X 33 15 (A) Resorcinoldiglycidyl ether X X 15 15 (B) X X X X 27 16 (A) Cycloaliphatic epoxyresin"' X X 9 16 (B) X X X X 37 17 (A) Triglycidyl ether of glycerol X X15 17 (B) X X X X 26 18 (A) Diglycidyl ether of bisphenol A X X 19 18(B) X X X X 19 (A) Diglycidyl ether of bisphenol A X X 12 19 (B) X X X X31 NOTE: Footnotes and 3 thru same as correspondingly numbered footnotesTable Ill-A Dacron "MOCA a trademark product of E. l. du Pont de Nemours8L Co., Inc.

"This resin was dissolved in isopropanol as 0.5% solution and 10 phrtctraethylenepentarnine was added as resin curvative in place of MOCA.

Compounding Recipe (A) Table IV.

TABLE III-A Fabric* Treatment A are Applicable to Other ElastomersFabric Treatment B Resin Cure m-aminophenol (Dry) (Heat) Bonded to PeelStrength Example Epoxy Resin Coating min./ (0.5% wt. (17 hrs./ (30 min./Elastomer (lbs/1" width No. (015% wt. epoxy in chloroform) C.) in water)27C.) 27C.) (Type) (Unaged) 20 Diglycidyl ether of bisphenol A X X X XCR" 35 NBR 44 SBR 28 21 Diglycidyl ether of bisphenol A X X X X NBR 3622 Polyglycidyl ether of phenoformaldehyde novolak resin X X X X NBR 3723 Resorcinol diglycidyl ether X X X X CR" 30 24 Cycloaliphatic epoxyresin X X X X CR" 37 25 Triglycidyl ether of glycerol X X X X CR 35 26Diglycidyl ether of bisphenol A X X X X CR" 33 27 Diglycidyl ether ofbisphenol A X X X X Cr 30 Trademark Firm Epoxy Equivalent Viscosity cps.Araldite 6020 Ciba Products Co. 196-208 l6,00020.000 Epon 828 ShellChemical Co. -192 10,000-16,000 CR Polychloroprene EPN l 139 CibaProducts Co. 172-179 17,000 NBR Butadiene-acrylonitrile TABLEIII-A-continued Fabric* Treatment A Fabric* Treatment B Resin Curem-aminophenol (Dry) (Heat) Bonded to Peel Strength Example Epoxy ResinCoating (60 min./ (0.5% wt. (17 hrs./ (30 min./ Elastomer (lbs./1" widthNo. (0.5% wt. epoxy in chloroform) 165C.) in water) 27C.) 27C.) (Type)(Unaged) ERE 1359 Ciba Products Co. 128 500 copolymer Unox 221 UnionCarbide Co. 221 Epon 812 Shell Chemical Co. 140-160 100-170 Araldite6004 Ciba Products Co. 185 5000-6000 SBR Butadiene-styrene Epon 1001Shell Chemical Co. 450-550 solid copolymer Dacron "Compounding recipesee Table IV.

TABLE Iv bisphenol A (Araldite 6020) and 10 phr of the epoxy curativemethylenebis-orthochloroaniline. The fabrics Elastomer CompoundingRecipes Compounding Recipe (A) (B (C) were gently agitated in thisemulsion for about a minute and then hung up at room temperature (about27 C.) gggzmgiggzzgz; g8 for about 16 hours, and then were heated 60minutes at polybutadiengacrylonitrilea 100 165C. in an air oven to atleast partially cure the epoxy gg y i g fiyi 10(1) resin upon the fibersof the fabric. a l y amme 3O The treated cotton and nylon fabrics werethen each garlic? black divided into four pieces, the first of which wasreserved eno ic resin polybmadiene acrylonmue, l5 25 for testing withoutfurther treatment, while the other Stearic acid 1 1 three were variouslyafter-treated. The second piece of Pdyelhylenc 1 each was after-treatedby dipping it into a 0.5% aque- Hexamethylenetetramme 1.9 3.0Tetramethyl thiuram lfld lo 02 ous solution of m-aminophenol, afterwhich it was dried lSzulfu]: d 9 q o 2.0 16 hours at about 27C. and thenwas heated about 30 Gill e ea 8 D Pba 4) 10 30 minutes at 165C. in anair oven. Temp 16500 (X) X X x The third piece of cotton and nylonfabric was after- Time, 60 45 treated in a RF dip of 1% resin solidswhich was aged a trademark product of E. l. du Pont de Nemours and Co.,Inc. a trademark product of E. I. du Pont de Nemours and Co., Inc.

' Neoprene GNA 2 Neoprene WB 5 I-Iycar 1002 a trademark product of B. F.Goodrich Chemical Co. 4 SBR-1502 5 Hi-Sil 233 a trademark product ofPittsburgh Plate Glass Co. 6 Philblack A a trademark product of PhillipsPetroleum Co. a trademark product of Hooker Chemical Corp.

Durez 12686 Poly B-D resin CN-l5 a trademark product of Atlantic A/CPolyethylene 617A a trademark product of Allied Chemical Corp. Monex atrademark product of Uniroyal, Inc.

Examples 28 through 35 (Table V) about 2 H2 hours before use. The fourthpiece was after-treated by dipping in a mixture of equal parts by weightof a portion of the same RF dip (aged about 2 U2 hours) and of a 1%solution of m-aminophenol and dried 16 hours at 165C.

The resorcinol-formaldehyde referred to as RF resin was made with a 1:2molar proportion of resorcinol to formaldehyde, and solium hydroxide wasemployed as a catalyst in the amount of 5% based on the dry solidsweight of the RF resin, and the resin was diluted with water to 1% byweight concentration.

The four pieces each of variously treated cotton and nylon fabric werethen laminated to a polychloroprene compound A of Table IV and testspecimens were cut from the laminates after they were cured. The improved adhesion provided by these after-treatments is shown in the peelstrength data of Table V.

The peel strength data in Table V teaches that cotton fabric and nylonfabric polychloroprene laminates show beneficial increase in peelstrength in the same manner as polyester fabric when either the fabricwith epoxy resin coating alone or the fabric with epoxy resin coatingplus resorcinol-formaldehyde coating overlay is after-treated withaqueous m-aminophenol.

TABLE V ADI-IESION OF COTTON AND NYLON FABRICS TO POLYCHLOROPRENEImprovement of Adhesion by After-Treatment of Fabrics with m-AminophenolFabric Treatment A Bonded to Polychloro- Epoxy Dry Cure Dry prene andTested Ex. Resin (16 hrs./ min./ (16 hrs./ Peel Strength, No. FabricEmulsion 27C.) C.) Fabric Treatment B 27C.) lb./1" width (X) (X) (X) 28Cotton X X X 17 29 Cotton X X X 1% aqueous m-aminophenol solution X 2030 Cotton X X X 1% RF dip X 25 31 Cotton X X X A mixture of equalproportions of 1% X 26 RF dip and 1% m-aminophenol aqueous solutionTABLE V-continued Fabric Treatment A Bonded to Polychloro- Epoxy DryCure Dry prene and Tested* Ex. Resin (16 hrs./ (60 min./ (16 hrs./ PeelStrength, No. Fabric Emulsion 27C.) 165C.) Fabric Treatment B 27C.)lb./1" width 32 Nylon X X X 16 33 Nylon X X X 1% aqueous m-aminophenolsolution X 26 34 Nylon X X. X 1% RF dip X 40 35 Nylon X X X A mixture ofequal proportions of 1% X 41 RF dip and 1% m-aminophenol aqueoussolution Compounding recipe A, Table IV.

"Nylon 66 a 1% by weight aqueous dispersion of resorcinol-formaldehyderesin in which the molar proportions of resorcinol and formaldehyde werein the ratio of 1:2, and sodium hydroxide was used as a catalyst in theamount of-% on the weight of the resin. The dispersion was aged for atleast 2 hours before application on the fabric or before mixing with theaqueous m-aminophenol and then applying to the fabric.

Recipe 1. Table l-A.

NOTE: Like advantages are attained with fabrics of mixed cotton andnylon fibers.

Examples 36 through 41 (Table VI) Examples 36 through 41 Table VI areconcerned with the adhesion of glass fiber fabric to a polychloroprene.Glass fiber fabric was first coated with an epoxy resin which was curedand thenafter-treated with maminophenol (both alone and in combinationwith resorcinobformaldehyde dip) and the adhesion to polychloroprenedetermined.

The glass fiber fabric was first cleaned thoroughly in a soldiumdichromate acid cleaning bath (see footnote to Table VI) followed byrinsing in plain water and dried. The fabric was then treated in achloroform solution containing 1% diglycidyl ether of bisphenol A resinand phr of the epoxy resin curative methylene-bisorthochloroaniline. Thefabric was agitated gently in this solution for about a minute, thendried four hours at 27C., and finally heated 60 minutes at 163C. to atleast partially cure the epoxy resin on the glass fibers.

A portion of this treated fabric was then after-treated by dipping in a0.5% by weight aqueous solution of maminophenol after which it was dried16 hours at 27C. followed by heating 30 minutes at 163C.

Two portions each were then cut from both the pieces of glass fiberfabric that has been coated only with the epoxy coating and that whichhad been also after-treated with m-aminophenol. One portion of each ofthese fabrics was treated in a 1% alkaline RF dip (as in Examples 21through 28) while the other was treated in a dip containing equal partsby weight of the 1% RF dispersion and a 1% solution of m-aminophenol (asin the examples of Table V). These fabrics were dried 16 hours at 27C.and then heated 10 minutes at 115C. before test specimens were made bylamination with a polychloroprene compound of Table IV, curing andtesting for peel strength of the laminate as described for Examples 1through 8 above in the section on Preparation and Testing of Specimens.Table V1 presents the peel test data obtained in this experiment whichagain teaches the beneficial effect of after-treatment of the coatedglass fabric with m-aminophenol to improve the peel strength of theglass fabric-elastomer laminates.

TABLE VI ADHESION OF GLASS FABRIC TO POLYCHLOROPRENE Effects ofm-Aminophenol After-treatment of Epoxy Resin Coated andResorcinol-formaldehyde Resin Coated Glass Fiber Fabric Coated FabricTreatment B Coated Fabric Treatment C Bonded to Po1y- Glass Fiber FabricTreatment A m-aminochloroprene (1% epoxy resin Dry Cure phenol Dry HeatDry Heat and Tested Ex. in chloroform with (4 hrs./ min./ (0.5 wt. (16hys./ 30 min./ (16 hrs./ (10 Peel Strength min./ No. 10 phr MOCA 27C.)163C.) aqueous) 27C.) 163C.) RF Dip 27C.) "C.) (1bs./1" width) 36 X X X17 37 X X X X X X 26 38 X X X 1% RF dip X X 21 39 X X X A mixture of X X24 equal proportion of 1% RF dip and 1% m-aminophenol aq. solution 40 XX X X X X 1% RF dip X X 24 TABLE VI-continued Coated Fabric Treatment BCoated Fabric Treatment C Bonded to Poly- Glass Fiber Fabric* TreatmentA m-aminochloroprene (l% epoxy resin** Dry Cure phenol Dry Heat Dry Heatand Tested Ex. in chloroform with (4 hrs./ (60 min./ (0.5 wt. (l6 hys./30 min./ (16 hrs./ Peel Strength min./ No. 10 phr MOCA 27C.) 163C.)aqueous) 27C.) 163C.) RF Dip 27C.) C.) (lbs./l width) 4i X X X X X X Amixture of X X 26 equal proportions of l% RF dip and 1% m-aminophenolaq. solution Glass fiber fabric cleaned with cleaning mixture forchemical glassware consisting of 800 cc concentrated sulfuric acid 92 g.sodium dichromate and 458 cc of water.

"Araldite 6020. a trademark product of Ciba Products Co.. see footnote,Table III-A A trademark designation of E. I. du Pont de Nemours 84 Co.,Inc. for methylene-bis-orthochloroaniline.

See footnote, Table V.

For compounding recipe see. Table III-A and compound was cured 60min/165C.

Compounding recipe A, Table IV.

Examples 42 and 43 are derived from an experiment in which six differentafterdips containing m-aminophenol aqueous solution,resorcinol-formaldehyde resin dispersions, and various combination ofthese dips were applied to six portions each of two polyester fabricsthat had been first treated with epoxy resin emulsions.

In Example 42 a piece of the polyester fabric dacron was first dippedinto an emulsion containing 1% DGEBA* resin solids prepared according torecipe I, Table LA and described under Examples 1 thru 8 above in thesection on Preparation of Epoxy Emulsions. The fabric was then dried 16hours at 27C. followed by curing 30 minutes at 165C. Diglycidyl ether ofbisphenol A.

In Example 43, a portion of polyester fabric was treated in an epoxyemulsion identical with that of Example 42 except that in addition toits 1 epoxy resin' solids it also contained 10 phr of the epoxy resincurative methylene-bis-orthochloroaniline. After the fabric was dippedinto the epoxy emulsion with gentle agitation for about a minute it wasdried 16 hours followed by curing 30 minutes in an air oven at 165C. andthen was divided into six portions and dipped as described hereafter.

The six dips used in after-treating the six portions each of the twofabrics of Examples 42 and 43 were as follows:

1. an alkaline RF dip containing 1% RF resin solids and in which themolar ratio of resorcinol to formaldehyde was I to 1.5. Sodium hydroxidewas employed as catalyst in the amount of 5.5 parts per hundred resinsolids. The dispersion was made as a 2% stock aqueous solution and aged2 hours before it was diluted to 1% and then was aged 1 more hour beforeuse.

2. A resin dispersion prepared like dip No. (l except that half of theresorcinol was replaced with maminophenol. This resulted in an opaquedispersion of partially particulate resin.

3. A resin dispersion prepared like dip No. (1) above except that all ofthe resorcinol was replaced with m-aminophenol. The dispersion wasopaque yellow and was aged 2% hours before use, at which time anexamination of a portion of the dispersion under a microscope showedthat the resin was present as spherical particles which were less than amicron in diameter and exhibited Brownian movement.

4. A resin dip prepared from half of the 2% stock dispersion of RF resinof dip No. (l) (aged 2 hours) by adding to it an equal weight ofm-aminophenol solution in which the weight of m-aminophenol equalled theweight of resorcinol.

5. A resin dip prepared from half of the 2% stock dispersion of dip No.(2) (aged 2 hours) by adding to it an equal weight of aqueous solutionof m-aminophenol in which the weight of m-aminophenol equalled thecombined weights of resorcinol and m-aminophenol in the resin of dip No.(2).

6. A resin dip prepared from half of the 2% stock dispersion of dip No.(3) (aged 2 hours) by adding to it an equal weight of aqueousm-aminophenol solution in which the weight of m-aminophenol was equal tothe weight of the m-aminophenol in the m-aminophenol-formaldehyde resinof dip No. (3).

The 12 pieces of polyester fabric treated by dipping in the sixdispersions described above were dried about 16 hours at 27C. Adhesiontest specimens were then prepared by laminating the fabrics to apolychloroprene compound A, Table IV, by curing the laminates 60 minutesat C. and then cutting test specimens from it as described for Examples1 through 8 in the section above on Preparation and Testing ofSpecimens." Peel test data obtained in these tests is presented in TableVII.

From the data in Table VII the following conclusions can be drawn:

1 If the fabric is only coated with an epoxy resin then after-treatmentwith m-aminophenol will greatly enhance the bonding to elastomers;

2. if the fabric is treated with a. an epoxy resin and with b. aphenoplast of the type of resorcinol-formaldehyde,resorcinol-m-aminophenol-formaldehyde or m-aminophenol-formaldehyde thenthe adhesion to elastomers is greatly enchance by treating withm-aminophenol either between the epoxy coating and the phenoplastcoating or after the phenoplast coating.

TABLE VII ADHESION OF POLYCHLOROPRENE COMPOUND TO VARIOUSLY TREATEDPOLYESTER FABRICS (Peel Strength in lbs/l Width Given in Columns (1)thru (7)) I Example Various 2nd Fabric Treatments*** No. 1st FabricTreatment RF R-m-AP-F m-AP-F (l) m-AP (2) m-AP (3) m-AP (Dacron FabricTreatment) (1) (2) (3) (4) (5) I 42 1% epoxy emulsion dip and cured 30min./ 23 18 26 27 33 30 165C. 30 min/165C. 43 1%epoxy emulsion dip plusphr MOCA** and cured 30 min/165C. 23 16 30 35 35 36 :After the Dacronfabric was dipped it was then atmospherically dried and laminated topolychloroprene compounded according to recipe (A). 'i'a'nie W and thecompound was cured 60 min. at 165C. A trademark designation of E. I. duPont de Nemours and Co. Inc. for methylene bis-orthochloro-aniline.

*"RF RF resorcinol-formaldehyde. R resorcinol. F formaldehyde. m-APm-aminophenol. (1) 1% solids dispersion. Molar ratio of resorcinol toformaldehyde was 1:1 .5v Sodium hydroxide was catalyst in the amount of5.5 phr. Dispersion was made as a 2% stock solution. then was aged 2hours. diluted to 1% and aged 1 more hour before use. (2) Like (1) aboveexcept half of the resorcinol was replaced with m-aminophenol. 1 (3)Like (1) above except that m-aminophenol completely replaced theresorcinol of l Dispersion was opaque yellow, Particles were l u. insize.

(4) Prepared from half of the 2% solution of l) aged 2 hours by addingto it an equal weight of aqueous solution of m-AP in which the weight ofm-AP equalled the weight of resorcinol in the resin of l l (5) Preparedfrom half of the 2% stock solution of (2) aged 2 hours by adding to itan equal weight of aqueous solution of m-AP in which the weight of m-APequalled that of the resorcinol and m-AP of the resin of (2). (6)Prepared from half of the 2% stock solution of (3) aged 2 hours byadding to it an equal weight of aqueous solution of m-AP in which theweight of mAP equalled that of the m-AP in the resin of (3).

The m-aminophenol to 45 a dip thereof may be m-aminophenol in an amountequal to the weight of readded to the aqueous RF resin or RFL resinbefore drysorcinol in the RFL dip and dissolved in water equal to ingthereof, and preferably the aqueous RF or RFL one-half the weight of RFLdip. The m-aminophenol resin is essentially free of formaldehyde toavoid having can advantageously be combined with the elastomer suchformaldehyde react with the m-aminophenol fablatex especially with thebutadiene-styrene-vinylpyriric. convert dine latex (Gen-Tac latex).

to resin, which conversion could render the m- The RFL dip of Example45A was prepared as folaminophenol ineffective for the purposes of thisinvenlows: 11 parts resorcinol were added to a solution of tion. 1.5parts sodium hydroxide in 239 parts water, and

then 16.2 arts 37.5% formalin were added to rovide Examples 44 and 45(Table a proporti n of 2 moles formaldehyde to 1 mol: resor- Examples 44and 45 are concerned with the adhesion cinol. This dispersion was aged 2)6 hours at about of an SBR compound to a fabric woven from modified27C. and then added to a mixture of 86 parts polychlopolyester fibersproduced by the Celanese Corporation, roprene latex (Neoprene 635 latex,a trademark prodand show the improved adhesion resulting from the adnetof E. I. du Pont de Nemours & Co. Inc.) of 58% dition of m-aminophenolto RFL dips used in treating solids. This RFL clip was aged 1 hourbefore use.

this fabric. The RFL dip of Example 45B was prepared from a The fabricwas an adhesive activated 12.8 oz. portion of that 45A by adding to itm-aminophenol woven fabric containing Celanese type 790 yarn in theequal in weight to the resorcinol of the RFL dip and warp, and 797 (lowshrinkage equivalent) yarn in the dissolved in water equal in weight toone-half that of filling. the RFL dip.

In Example 44, Table VIII an RFL dip was made as Portions of thatmodified polyester fabric were follows: 33.2 parts by weight resorcinolwas dissolved dipped in each of the four RFL dips described above in asolution of 2.6 parts sodium hydroxide in 665 parts and then dried atleast 16 hours at 27C. Test speciwater and then 34.4 parts 37.5%formalin was added to mens were then prepared by laminating them to anprovide a proportion of 1.4 formaldehyde to l resorci- SBR compound (SeeTable VIII by the method denol. This dispersion was aged 1 16 hours andthen comscribed under Examples 1 through 8 above in the secbined with amixture of 390 parts by weight of a butadition on Preparation andTesting of Specimens. Peel ene-styrene-vinylpyridine-latex (Gen-Taclatex, a strength test data obtained for these four treated fabtrademarkproduct of the General Tire and Rubber rics is presented in Table VIII.

Co.) of 41% solids and 30 parts of an SBR latex (Plio- The data in TableVIII shows that when adhering lite 3757B latex, a trademark product ofthe Goodyear polyester fabric to butadiene-styrene-vinylpyridine Tireand Rubber Co.) of 66% solids plus 70 parts water. elastomers employinga resorcinol-formaldehyde-latex This RFL clip was aged 24 hours beforeuse. dip the addition of m-aminophenol to the dip improved The RFL dipused in Example 448 was made from a the adhesion of the laminate.

portion of that dip from Example 44A by adding to it TABLE VIII Effectof m-Aminophenol with RFL Dips on Adhesion of Modified Polyester Fibers*to SBR Compound Adhesion to SBR Compound Example No. RFL Dip PeelStrength, lb./1" width 44A RFL dip contained 13% by weightbutadiene-vinylpyridine- 20 styrene latex solids. 1.6% SBR latex solids.and 3.6% RF solids 443 As in 44A except for addition of m-aminophenol inamount equal 27 in weight to the RF resin solids in the RFL dip. 45A RFLdip contained 8.5% by weight polychloroprene latex solids 12 4.2%butadine-vinylpyridine-styrene latex solids, 4.2% SBR Latex solids and2.9% RF solids 458 As in 45A except for the addition of m-aminophenolequal in a weight to that of RF resin in the RFL clip 25 Anadhesive-activated polyester 12.8 oz. woven fabric containing Celanesetype 790 yarn in the warp and type 797 (low shrinkage equivalent yarn)in the filling. The RFL dip was prepared by first reacting 33.2 parts byweight resorcinol and 344 parts of 37% formalin in a solution of 2.6parts sodium hydroxide in 665 parts water This RF clip was aged 1% hoursand then added to a mixture of 390 parts of Gen-Tar: Latex(butadiene-styrene-vinylpyridine terpolymer). 30 pt Pliolite Latex37571;,

66% solids and 70 pts. water. This RFL dip was aged 24 hours before use.

The RFL dip was prepared by first reacting 1 1 parts by weightresorcinol and 16.2 parts 37% formaldehyde in a solution of 1.5 partssodium hydroxide in 239 parts water. This RF dip was aged 2V2 hours atabout 27C. and then added to a mixture of 86 parts of Neoprene 635 latex(a polychloroprenc latex of 58% solids. E. l. du Pont de Nemours and Co.Inc. 38 parts Pliolite 3757E (a 66% solids SBR latex. Goodyear Tire 8LRubber Co.) and 61 parts Gen-Tac latex (a butadienestyrene-vinylpyridincterpolymer latex of about 41% solids, General Tire and Rubber Co.) and141 parts water. This dip was aged 1 hour before use.

100 SBR 1502, 50 HAF black. 3 zinc oxide. l stearic acid. l Santocure NS(n-tert-butylJ. benzothiazole sulfonamide. Monsanto Co.) 1.75 sulfur. 1Wingstay 100 (mixed diaryl paraphenylenediamines) Goodyear Tire andRubber Co. Fabric-elastomer laminate cured 45 min/165C.

Examples 46 and 47 (Table IX) Examples 44 and 47 are concerned with theadhesion to a polychloroprene compound of the polyester Dacron and nylon66 fabrics both of which were treated with aqueous dips containing equalparts by weight of an emulsified epoxy resin and an acidic RF resin inaqueous dispersion while portions of each were aftertreated withm-aminophenol in aqueous solution.

The acidic RF resin dispersion was prepared as follows: 6.4 parts byweight resorcinol was dissolved in a solution of 1 partalkylarylpolyether alcohol (Triton X- 155, a trademark product of Rohmand Haas Co.) and 30 parts of a 1% aqueous solution of hydrochloric acidwere added followed by 9.4 parts 37.5% formalin. This mixture in a jarwas rotated end-over-end for four 16 hours at 27C. followed by curing 30minutes at 165C.

Adhesive test specimens were prepared from the above four fabrics bylamination with a polychloroprene compound A, Table IV, as described forExamples 1 through 8 in the section of Preparation and Testing ofSpecimens. Peel strength test data for these treated fabrics ispresented in Table IX. When the aqueous epoxy emulsion and theresorcinol-formaldehyde aqueous disperson are combined in a single dipwhich is cured on the fibrous material to provide adhesion to rubber,then there is an advantage in treating the fabric first with thecombination dip and drying the same and then with an aqueousm-aminophenol dip which in turn is dried in order to promote or improvethe strength of the bond obtained.

TABLE IX Effect of After-Treatment with m-Aminophenol on Adhesion toPolychloroprene of Fabrics Pro-Treated with a Mixture of Epoxy Emulsionand RF Resin After-Treatment with m-aminophenol Bonded toPolychloroprene are Tested Example Peel Strength No. Base Fabric FabricTreatment A Cure Fabric Treatment B Cure (lbs./1 width) 46A PolyesterMixture of 1% by weight 30 min./ None 24 emulsion of cycloali- 165C.phatic epoxy resin* and equal weight of a 1% dispersion of RF resin"made with acid catalyst 468 Polyester 0.5% aq. solution 30 min./ 26

of m-aminophenol 165C. 47A Nylon None 36 475 Nylon 0.5% aq. solution 30min./

of m-aminophenol 165C.

' Unox Epoxide 221 a trademark product of Union Carbide Corp. employedin Recipe 1. Table l-A. "Prepared by the reaction of 6.4 parts by wt.resorcinol and 9.5 parts 37.5% formalin in a solution of 30 parts 1%HCl, 1 part Triton X-l (alkylarylpolyether alcohol, Rohm 8c Haas C0.) 30parts isopropanol and 40 parts water. This mixture was reacted fivehours at 27C. in a ball mill, then was diluted with water to provide a1% resin dispersion.

Polyethylene terphthalate Dacron Nylon 66.

Compounding Recipe A. Table IV.

hours, at the end of which time the RF resin was slightly milky inappearance. It was diluted to 1% resin solids with water and was thenadded to an equal weight of a 1% resin solids emulsion of acycloaliphatic epoxy resin (Unox Epoxy 221, a trademark product of UnionCarbide Co.).

In Examples 46A and 47A, pieces of polyester and nylon fabricsrespectively were each treated by immersion and gentle agitation forabout one minute in the epoxy-RF dip described above and then were dried16 hours at 27C. followed by curing 30 minutes at 165C. In Examples 46Band 47B portions of these fabrics were then after-treated by dipping in0.5% aqueous solutions of m-aminophenol after which they were driedExamples 48 through 51 (Table X) Examples 48 through 51 concern theadhesion of polyester fabric, Dacron, to an SBR compound and presents acomparison of the effects of after-treatments of the fabric with RFLdips both with and without the addition of m-aminophenol.

In Examples 48 and 49 the polyester fabric was first treated by dippingin a 0.5% chloroform solution of a DGEBA resin (Araldite 6020), then wasdried 4 hours at 27C. and cured 30 minutes at C. after which it wastreated in Example 49 with 0.5% aqueous maminophenol solution, was dried16 hours at 27C., and cured 30 minutes at 165C. The fabrics were thencut into two portions, one of which was treated with RFL 29 dip whilethe other was treated with a portion of the same RFL dip plusm-aminophenol equal in weight to the resorcinol of the dip. The recipefor the RFL dip of Example 44 is given in footnote (1) of Table VIII.

In Example 50 a piece of polyester fabric was first treated with anemulsionn containing 1% epoxy resin solids (Araldite 6020) and 16 phrm-aminophenol. The fabric was dried 16 hours at 27C. and then cured 60minutes at 165C. The fabric was then divided into two portions, one ofwhich (Example 50A) was treated with the RFL dip described in footnote(1) Table VIII while the other (Example 50B) was treated with the sameRFL dip plus m-aminophenol equal inweight to the resorcinol of the RFLdip.

In Example 51 the polyester fabric was treated with a 1% solution of aDGEBA resin in chloroform containing also phrmethylene-bis-orthochloroaniline, after which it was dried 2 hours at27C. followed by curing 60 minutes at 165C. The fabric was then dividedinto 2 pieces; fabric designated 51A was treated in the RFL dipdescribed in footnote (1) of Table VIII while the other fabric, 51B, wastreated in a portion of the same dip to which was added m-arninophenolequal in weight to the resorcinol of the RFL dip.

These fabrics, after treatment with RFL dips, were dried 16 hours at27C. and then test specimens were prepared from laminates of the fabricswith an SBR compound (see Table X), by the method described for Examples1 to 8 above in the section on Preparation and Testing of Specimens.Peel test data for these variously treated fabrics is presented in TableX.

The data in Table X shows the adhesion of Dacron to SBR, employing epoxycoatings at least in part cured to the Dacron with heat and with orwithout the aid of curative material and with a further coating of RF Ldip dried thereon, and improved by applying m-aminophenol prior to theRFL dip or in admixture with the RFL dip and drying the same beforeassembly with the vulcanizable elastomer and vulcanization thereof.

Example 52 (Table XI) Example 52 is concerned with the adhesion of thepolyester fabric Dacron to a polychloroprene compound and demonstratesthe effect ofa m-aminophenol aqueous dip as an after-treatment appliedto fabric previously treated with an aqueous dip containing epoxy resin,m-aminophenol, RF resin, and an elastomer latex and cured. The aqueousepoxy-RFL dip was prepared as follows.

First an RF resin dispersion was prepared by dissolving 3.2 parts byweight resorcinol in 25 parts 1% aqueous solution of sodium hydroxideand adding to this 4.7 parts 37.5% formalin. This was allowed to age for2 hours at about 27C. and then it was diluted with water to form a 1%dispersion.

To the RF resin dispersion was added 122 parts by weight of abutadiene-styrene-vinylpyridine terpolymer latex (Gen-Tao) diluted withwater to contain 5 parts solid and also an emulsion containing 1% DGEBAresin solids (Araldite 6020) and m-aminophenol in the amount of 16 partsby weight per hundred parts epoxy resin.

Polyester fabric was treated in this dip by immersion and gentleagitation for about a minute, then was dried 16 hours at about 27C.followed by heating 60 minutes at 165C. A portion of this fabric(Example 52A) was then reserved for testing while the balance (Example528) was dipped into a 0.5% aqueous m-aminophenol solution and dried 16hours at 27C.

These two fabrics were each laminated to a polychloroprene compound A,Table IV, and test specimens cut from the cured laminates as describedfor Examples 1 through 8 above in the section of Preparation and Testingof Specimens. The comparative peel strength test data for these twotreated fabrics is reported in Table XI.

The data Table XI shows that the bond between Dacron and Neoprene,adhered with the aid of an aqueous emulsion of epoxy resin andresorcinol-formaldehyde TABLE X Effect of m-Aminophenol in RFLAfter-Treatment of Polyester Fabric Treated with Epoxy Resins onAdhesion to SBR Adhesion to Fabric Treatment A Fabric Treatment B FabricTreatment C SBR Compound Ex. Peel Strength No. Dry Cure Dry Cure Drylb./1" width 48A 0.5% chloroform solu- 4 hr./ 30 RFL dip 16 hr./ 11

min./ tion of epoxy resin* 27C. 165C. 27%. 48B RFL dip" m-aminophenol 2649A 0.5% chloroform solu- 4 hr./ 30 0.5% aqueous 16 hrs./ 30 RFL dip" 19min./ solution min./ tion of epoxy resin 27C. 165C. of m-aminophenol27C. 165C.

n r: I! u n n dip** m-aminophenol" 50A Emulsion of 1% epoxy 16 RFL dip16 hr./ 10

min./ min./ solids and 16 phr 27C. C. 27C. m-aminophenol 50B RFL dip"+m-AP 27 51A 1% solution by wt. 2 hr./ 60 RFL dip** 16 hr./ 12

min./ of epoxy resin con- 27C. 165C. 27C. taining 10 phr MOCA 51B RFLdip** m-AP 22 Araldite 6020. see Footnote. Table Ill-A. "See footnotetTable Vlll.

Polyethylene terephthalate, Dacron," a trademark product of E. I. duPont de Nemours & Col. Inc.

See footnote, Table V111.

A tr k u for mcthy JY'L m-Aminophenol added to RFL dip" in an amountequal to resorcinol in dip.

oaniline (E. l. du Pont de Nemours & Co., Inc.)

31 resin containing m-aminophenol of at least partially cured on theDacron before assembly with the Neoprene and vulcanization thereof, isimproved by an after-treatment with m-aminophenol dried thereon prior tothe assembly with the Neoprene and vulcanization thereof.

TABLE XI ADHESION OF POLYESTER FABRIC TO POLYCHLOROPRENE Effect of AfterTreatment with m-Aminophenol on Polyester Fabric Pre-Treated withCombination of Epoxy Resin Emulsion, m-Aminophenol. and RFL Dip Bondedto Polychloroprene Example Fabric* Treatment A Fabric Treatment BCompound and Tested No. Dry Heat Dry Peel Strength, lb./l width 52A Anaqueous emulsion of 0.79% total solids l6 hr./ 60 31 min./ 27C. l65C.consisting of approximately epoxy resin solids, 30% RF resin" solids,30% elastomer as latex solids, 4.8% m-aminophenol, and 6% emulsifier 752B Same as 54A above 0.5% aqueous 16 hr./ 41

m-aminophenol 27C.

Dacron polyethylene terephthalate a trademark product of E. I. du Pontde Nemours and Co. Inc.

"Compound recipe A, Table IV and cured 60 minutes at l65l Araldite 6020,a trademark product of Ciba Products Co. See recipe I. Table I-A.

See footnote, Table VI.

"Gen-Tao latex a terpolymer of styrenev vinylpyridine and butadiene. atrademark product of General Tire & Rubber Cov Equal parts by weight ofpolyoxyethylene sorbitan monostearate (Tween 60". Atlas ChemicalIndustries) and Duponol ME (a lauryl alcohol sulfate, E. I. du Pont deNemours & Co. Inc.

Examples 53 and 54 (Table XII) Examples 53 and 54 are concerned with theadhesion of nylon 66 fabric to polychloroprene and demonstrate theeffect of m-aminophenol after-treatment on nylon treated with RF resinin the form of particles of greater than colloidal size.

In Example 53 an RF resin was prepared using an acid catalyst asfollows: 6.4- parts by weight resorcinol was dissolved in 70 parts waterand then 30 parts 1% aqueous hydrochloric acid was added followed by 9.4parts 37.5% formalin. This solution was allowed to stand at about 27C.for 1 hour and minutes, by which time an off-white precipitate (slightlypink) had formed in the bottom of the beaker containing the solution.The dispersion including precipitate were put into a small blender andrun at high speed for about 5 minutes to break up the soft RFprecipitate. Examination of a sample of the dispersion under amicroscope then showed the resin to be present in the form of irregularspherical particles ranging in size from 3 to 1 1 microns in diameterwith the majority in the 4-8 micron size range. When dry the sphereswere bright red. This RF dispersion was diluted with water so that theresin solids were reduced to 1% by weight. One piece of nylon fabric wasdipped into the dispersion described above and then dried overnight at27C. (Example 53A). Then a portion of this fabric was cut off, dippedand the mixture was ball-milled in a glass container for 2 hours. Thedispersion was then opaque and a pale pink in color. When a sample ofthe dispersion was examined under a microscope it was seen that theresin was in the form of regular spherical globules in the range of 1.5to 3.5 microns in diameter and exhibiting Brownian movement. Thisdispersion was diluted with 883 parts water to reduce the RF solids to1%.

A piece of nylon fabric was treated in the above dispersion by immersionand gentle agitation for about a minute. Then it was dried 16 hours at27C. (Example 54A). A portion of it was then cut off and after-treatedwith a 0.5% aqueous solution of m-aminophenol (Example 54B) and driedagain 16 hours at 27C.

The four pieces of treated nylon fabric were then tested in laminateswith a polychloroprene compound A, Table IV, according to the proceduredescribed for Examples 1 through 8 above in the section on Method ofTesting the Strength of Fabric-Elastomer Bonds. The results of the peelstrength tests are presented in Table XII.

The results set forth in Table XII show that adhering nylon to Neopreneusing a particulate RF dip is im' proved when the nylon is given anafter dip with aqueous m-aminophenol. We have found that the particulateRF dip here referred to when used as adhesives provides fibrousmaterial-elastomer laminates having reduced stiffness as compared withlaminates employing conventional RF and RFL dips.

TABLE XII NYLON-POLYCHLOROPRENE ADHESION Effect of After-Treatment withm-Aminophenol on Nylon Treated with RF Particulate Dip Exam- FabricTreatment A Fabric Treatment B Bonded to Polychloroprene ple Dry DryCompound and Tested No. 16 hr./27C. 16 hr./27C. Peel Strength, lb./lWidth' 53A 1%dispersion of RF particles made X 41 with acid catalyst 53B1% dispersion of RF particles made X 0.5% m-aminophenol X 43 with acidcatalyst aqueous solution 54A 1% dispersion of RF particles made X 40with triethanolamine 54B 1% dispersion of RF particles made X 0.5%m-aminophenol X 46 with triethanolamine aqueous solution *Nylon 66"Compound recipeA, Table IV cured 60 min. at 165 This RF dispersion wasprepared by reaction of 6.4 parts by weight resorcinol with 9.4 parts37.5% formalin in a mixture of 30 parts 1% HC1 and 70 parts water. Thismixture was allowed to stand for about 100 minutes until a whiteprecipitate was observed. This was broken up by agitation in a blenderat high speed, then the mixture was diluted to 1% solids and used. Byexamining a sample of the dispersion under a microscope it was observedthat the RF resins were in the form of spherical particles and clustersof these particles. These particles ranged in diameter from about 3 to 11 microns.

"This RF dispersion was prepared by dissolving 6.4 parts by weightresorcinol in a solution of 1 part triethanolamine and 50 parts water.then adding 9.4 parts 37.5% formalin. After about minutes the solutionbecame cloudy and slightly pink. Thereupon it was diluted to provide a1% dispersion, and was allowed to stand for about 3 hours beforeemploying it as a fabric dip. By examination of a sample of thisdispersion under a microscope, it was determined that the resin waspresent in the form of spherical globules mostly in the range of 2.0-2.5microns in diameter.

Examples 55 and 56 (Table XIII) Examples 55 and 56 demonstrate theeffects of the addition of varying amounts of m-aminophenol to elastomerlatices used in RFL dips for the treatment of polyester fabric toimprove its adhesion to elastomer compounds.

The particular polyester fabric used in these examples was woven fromthe adhesive activated types 790 and 797 polyesteryarns produced byCelanese Corporation.

The latex to which the m-aminophenol was added was a mixture of abutadiene-vinylpyridine-styrene terpolymer latex (Gen-Tao latex, GeneralTire and Rubber Company) and an SBR latex (Pliolite 3757B, Goodyear Tireand Rubber Co.) in the ratio of 5 parts vinylpyridine-terpolymer latexsolids to 1 part SBR latex solids. The m-aminophenol was added to thebutadiene-vinylpyridine-styrene-latex.

This mixture of latices was divided into four portions of 150 g., eachcontaining 60 g. solids. To the first (control) portion 100 g. purewater was added, while to the second portion 3 g. m-aminophenoldissolved in 97 g. water were added. Similarly to the third portion wereadded 6 g. m-aminophenol dissolved in 94 g. water, and to the fourthportion 12 g. m-aminophenol dissolved in 88 g. water. These latexmixtures were allowed to stand for 1 1a hours before 150 g. of analkaline RF dispersion containing 12 g. RF resin solids (of 1:2resorcinol-formaldehyde molar ratio) were added to each. This RF resindispersion had been aged 1 b hours before addition to the latex mixture.The RFL mixture thus obtained was aged for 1 hour before treatment ofthe polyester fabric by dipping pieces of it into each of the four RFLdips, respectively.

The four treated polyester fabrics were hung up to dry at roomtemperature overnight then were heated 10 minutes at 1 15C. They werethen formed into laminates with an SBR compound in a Carver press andthen the laminates were cured minutes at 165C. and specimens were cutfrom the cured laminates and were tested for peel strength. The resultsof these tests are presented in Table XIII and show that for bonding afabric material to an elastomer using an RFL dip, when m-aminophenol isadded to the elastomer latex which is combined with an aqueousdispersion of a resorcinol-formaldehyde resin then better adhesion isobtained than when the elastomer latex of such RFL dip does not containadded m-aminophenol.

Similarly, in practicing Example 45B, the m-aminophenol may be added toone or more of the elastomer latices, e.g. the polychloroprene latex,the butadienestyrene latex, and the butadiene-styrene-vinylpyridinelatex, and the thus improved latex composition can be used in formingthe improved RFL dip. Preferably the m-aminophenol is combined with thevinylpyridine polymer latex, in the ratio of about 10 partsm-aminophenol per 15 parts latex, dry basis, and this combination usedin the proportions set out in Example 45B provides the designatedquantity of m-aminophenol based on the RF resin.

TABLE XIII Effect of m-Aminophenol in Latex used in RFL Dips as Adhesivefor Modified polyester Fabric to SBR Elastomer Compound Adhesion to anSBR Compound of Modified Composition of RFL Dips Dispersion PolyesterFabric Treated with RFL Dips Example Latex Mixture RF Resin solids(laminates cured 6O min/165C.)

No. parts by weight Parts by wt. pphr Peel Strength, 1b./1" width 55A125 parts vinylpyridine terpolymer latex 150 20 29 (5O solids) (12solids) 26 parts SBR latex (10 solids) parts water 553 partsvinylpyridine terpolymer latex 20 37 (50 solids) (12 solids) 25 partsSBR latex (10 solids) 3 parts m-aminophenol (5 phr) 97 parts water 56A125 parts vinylpyridine terpolymer latex 150 20 38 (50 solids) (12solids) 25 parts SBR latex- (10 solids) 6 parts m-aminophenol (10 phr)TABLE XIII-continued Effect of m-Aminophcnol in Latex used in RFL Dipsas Adhesive for Modified polyester Fabric to SBR Elastomer CompoundAdhesion to an SBR Compound* of Modified Composition of RFL DipsDispersion Polyester Fabric Treated with RFL Dips Example Latex MixtureRF Resin solids (laminates cured 60 min./165C.) No. parts by weightParts by wt. pphr Peel Strength, lb./1" width 94 parts water 56B 125parts vinylpyridine terpolymer latex 150 20 39 (50 solids) (l2 solids)25 parts SBR latex (IO solids) 12 parts m-aminophenol (2O phr) 88 partswater I SBR I502. 50 HAF black (Philblack 0, Phillips Petroleum Co.). I2,2'-methylene bis(4-methyl-6-tertiary-butyl phenol) (Antioxidant 2246.American Cyanamid Co.). 3 zinc oxide, 2 sulfur. 1.25 N-oxydiethylenebenzothiazole-Lsulfonamide (Nobs Special, American Cyanamid Col).

"Celanese type 790 adhesive activated polyester was used as warp in thisfabric while type 797 (low shrinkage equivalent) was used in filling TheRF resin was prepared in one master solution for all seven dips asfollows: 53.8 g. resorcinol was dissolved in 420 g. 1% NaOH. then 79 g.of 37.5% formalin and 497 g. water were added. after which thedispersion was aged for We hours before addition to the latex mixture.The RFL mixture was aged 1 hour before use. Gen-Tac latex, General Tireand Rubber Co.

Pliolite 3757E. Goodyear Tire and Rubber Co. (Reduced to 40% solids).

of the same RFL dip to which had been added 5 parts Examples 57 and 58(Table XIV) 20 by weight m-aminophenol per 8.5 parts RF resin. Examples57 and 58 demonstrate the improved adhe- The basic RFL dip of theseexamples was prepared as sion between polyester and an SBR compoundobfollows: 11 parts by weight resorcinol was combined tained by addingm-aminophenol to the second clip of a with 320.5 parts water, 0.3 partssodium hydroxide, 2-dip commercial type fabric treatment in which theand 16.2 parts 37% formalin and this mixture was alfirst clip was adispersion containing a blocked diisocyalowed to age for six hoursbefore combination with 250 nate and an epoxy resin, while the secondwas an RF L parts 40% vinylpyridine terpolymer latex (Gen-Tac, dipcontaining vinylpyridine terpolymer latex. General Tire and Rubber Co.)and l 1.3 parts 28% am- A 40% dispersion of the blocked diisocyanate wasmonium hydroxide. This dip was divided in half and to first prepared byball-milling overnight a mixture of one half 5 parts m-aminophenoldissolved in 100 parts parts of the his phenol adduct ofmethylene-bis(4-phe- 30 water were added. nyl isocyanate) (Hylene MP, E.I. du Pont de Nemours Pieces of polyester fabric, pre-treated asdescribed & Co. Inc.) and 1 part of sulfonated ester of a fatty acidabove were dipped into each of the above RFL dips, (Aerosol OT, AmericanCyanamid Co.) dissolved in 14 dried 17 hours at about 27C. and thenheated 30 minparts water. utes at 165C. before being formed into testlaminates In the blender was combined 9 parts of the I-Iylene 35 with anSBR compound. MP dispersion containing 3.6 parts of the dry blockedTable XIV presents test data for the cured laminates diisocyanate, 4parts of a 1% aqueous solution of gum showing that m-aminophenol addedto the RFL dip tragacanth and 1.36 parts of a water dispersible drycontributed a significant increase in peel strength.

TABLE XIV ADI-IESION OF POLYESTER FABRIC TO SBR Improvement of AdhesiveStrength by Addition of m-Aminophenol to Second Dip of a Two-DipCommercial Adhesive Fabric Treatment Adhesion to SBR Compound Example I(laminates curd so min/165C.) No. Fabric Dip I Dry Fabric Dip II DryHeat Peel Strength, lb./1" width 57 5% solids dispersion of 3.6 parts 6hr./ 20% solids 17 hr./ 30 23 min./ blocked diisocyanate* and 27C. RFLclip 27C. 165C. 1.36 parts epoxy resin" 5 min./ 1 C. 58 5% solidsdispersion of 6 hr./ solids RFL 17 hr./ 30

min./ 3.6 parts blocked diisocyanate* 27C. dip 5 27C. 165C. and 1.36parts epoxy resin** 5 min./ parts m-aminophenol per 8.5 parts RF resinBis phenol adduct of methylene bis-(4-phenyl isocyanate) I-Iylene MP, E.I. du Pont cle Nemours and Co. Inc.

"Epon 812. Shell Chemical Co.

Dacron. E. I. du Pont de Nemours 8L Co.. Inc.

Prepared so as to contain 100 parts vinylpyridine terpolymer latexsolids (Gen-Tao, General Tire and Rubber Co.). 17.3 parts RF resin (madewith 0.3 parts sodium hydroxide catalyst and aged 6 hours) and 1L3 parts28% ammonium hydroxide.

100 SBR 1502. I 2.2'-methyIene-bis(4 methyl-6-tertiary-butyl phenol)(antioxidant 2246, American Cyanamid Co.) HAF black (Philblack 0.Phillips Petroleum Co.) 3 zinc oxide. 2 sulfur 1.25 Nmxydiethylenebenzothiazole-Z-sulfonamide (Nobs Special. American Cyanamid Co.

epoxy resin (Epon 812) and 86 parts water and agitated to form adispersion. Examples 59 and 60 (Table xv) Dacron polyester fabric wasdipped into the above Examples 59 and 60 demonstrate the effect onadhedispersion and dried 6 hours at about 27C. followed by sion ofadding m-aminophenol to RFL dispersions in heating 5 minutes at 115C.This treated fabric was which the RF resin was made in the presence ofthe then divided into two pieces, one of which (Example latex (Gen-Tao,a vinylpyridine terpolymer latex pro- 57) was dipped into a 20% solidsRFL dip while the duced by General Tire and Rubber Co.). This RFL dipother (Example 58) was dipped into a second portion was prepared asfollows: 11 parts resorcinol was dissolved in a solution of 0.3 partssodium hydroxide in An RF resin dispersion was first prepared by combin130 parts water and added to 250 parts Gen-Tac latex ing 6.4 partsresorcinol, 100 parts water, 0.5 parts socontaining about 100 partspolymer solids then was dium hydroxide and 9.5 parts 37% formalin. Thiswas added 16.3 parts 37% formalin in 191 parts water and aged for 2 1%hours at about 27C. then diluted with the mixture was aged at 27C. for 2V2 hours. Then 1 1.3 5 water to provide a 2% dispersion of RF resinsolids. In parts 28% ammonium hydroxide was added and the Example 61,100 parts of this 2% dispersion were didispersion was allowed to standfor another half hour luted with an equal weight of water and a piece ofnylon before use. 66 fabric was dipped into the resultant 1% dispersionThe RFL dispersion was then divided into two equal and then dried atabout 27C. for 16 hours. In Example portions each containing 8.5 partsRF resin. To one 62, to 100 parts of the 2% dispersion was added anportion (Example 59) was added 100 parts by weight equal weight of a 2%aqueous solution of m-aminowater and to the second portion of thedispersion (Exphenol. A piece of nylon fabric was similarly dipped ample60) was added a solution of 5 parts m-aminointo this mixture and dried.

phenol in 95 parts water. Laminates were prepared from these two piecesof Pieces of modified polyester fabric (woven of Celantreated nylon anda compound of an elastomeric coese Corporations types 790 and 797 yarns)were impolymer of vinylidene fluoride and perfluoropropylene mersedin'the above RFL dips and then dried at about (Viton B, E. I. du Pont deNemours and Co. Inc.). 27C. for 16 hours followed by heating 10 minutesat Table XVI presents the peel test data obtained from 1 C. testspecimens cut from the cured laminates.

TABLE XVI ADHESION OF NYLON FABRIC TO A FLUOROELASTOMER COMPOUND*Improvement of Adhesion by Addition of m-Aminophenol to RF Fabric DipCure of Nylon- Drying of Fluoroelastomer containing m-aminophenol in anamount by weight equal to that of the RF resin.

100 parts copolymer of vinylidene fluoride and perfluoropropylene (VitonB, E. I. du Pont de Nemours & Co. Inc.). 15 low-activity magnesium oxide(Maglite Y. Merck & Co. Inc), 20 medium thermal carbon black, (Thermax.R. T. Vanderbilt Co.), 1 hexamethylenediamine carbamate (Diak No. l. E.I. Du Pont de Nemours and Co. Inc.).

After 60 minutes gradual rise in temperature from 27 to 165C.

The RF dips of Examples 61 and 62 were prepared as follows: 6.4 partsresorcinol. 100 parts water. 0.5 parts sodium hydroxide and 9.5 parts37% formalin were combined and the combination aged for 2% hours, afterwhich it was diluted with water to provide a 2% RF solids dispersion. InExample 61, 100 parts of the 2% dispersion was diluted with an equalweight ofwater to provide a 1% RF dispersion. In Example 62. to 100parts of the 2% dispersion was added an equal weight of a 2% aqueoussolution of m-aminophenol.

The 2 pieces of RFL treated polyester fabric were then each formed intotest laminates with sheets of an Examples 63-93 SBR compound and thelaminates pre-heated 20 min- 40 Examples 63-93 are directed to furtherembodiments utes at 115C. then cured minutes at 165C. Table of theinvention wherein the applicants discovery is ap- XV presents test datashowing that the addition of mplied to the improvement of adhesive bondswith comaminophenol resulted in a considerable improvement binations ofsubstrate other than those set out in Exam in adhesion. ples 162, andwith Examples 1-62 illustrate the gen- Tabe eral applicability of theinvention of the improvement TABLE XV RFL DIPS IN WHICH RF RESIN WASFORMED 1N PRESENCE OF LATEX Effect of Addition of m-Aminophenol onAdhesion of Modified Polyester Fabric to SBR Compound** Adhesion to SBRCompound Laminates cured 60 min./165

Example No. RFL Dip Drying of Fabric Peel Strength, lb./in. width 59 17parts RF resin formed in presence of 100 parts vinyl- 16 hr. at 27C. -l-32 pyridine terpolymer latex 1 (dry basis) 10 min. at 1 15C. 60 As inExample 59 except for the addition of 5 parts 16 hr. at 27C. 42

m-aminophenol per 8.5 parts RF resin 10 min. at 1 15C.

An adhesiveactivated polyester 12.8 oz. woven fabric containing Celanesetype 790 yarn in the warp and type 797 (low shrinkage equivalent yarn)in the filling. "See Table XIV for compounding recipe.

The latex used was Gen-Tao. General Tire and Rubber Co.

The RFL dip was prepared as follows: 11 parts resorcinol was dissolvedin a solution of 0.3 parts sodium hydroxide in 130 parts water and addedto 250 pans Gen-Tac latex containing 100 parts polymer solids, 16.3parts 37% formalin in 191 parts water was then added and this mixturewas aged 2% hours at 27C. after which 11.3 parts of 28% ammoniumhydroxide was added and the dispersion was aged for another half hour.It was then divided into 2 equal portions to the first of which (Example59) 100 parts plain water were added, while to the second (Example 60)were added 5 parts m-arninophenol dissolved in parts water.

of phenoplast adhesives, for adhering wood, metal, plastics, glass,rubber, paper, etc., substrates to like or Example 61 and 62 differentsubstrates. Examples 61 and 62 are concerned with the adhesion 65 ofnylon fabric to a fluoroelastomer compound and demonstrate improvementof adhesion resulting from A mill-mixed polychloroprene masterbatchconsistthe addition of m-aminophenol to RF fabric dips. ing of partsNeoprene AC (E. I. du Pont de Ne- Examples 63-68

1. IN THE FORMATION OF A BOND BY VULCANIZING A VULCANIZABLE ELASTOMER TOA FIBROUS MATERIAL WITH THE AID OF AN ADHESIVE DIP OF PHENOPLAST DRIEDON THE FIBROUS MATERIAL BEFORE ASSEMBLY WITH THE ELASTOMER ANDVULCANIZATION THEREOF, THE IMPROVEMENT WHICH COMPRISES ALSO APPLYING TOTHE FIBROUS MATERIAL, AND DRYING THERON BEFORE SUCH ASSEMBLY, A DIP OFUNRESINIFIED M-AMINOPHENOL.
 2. An improvement as claimed in claim 1, inwhich the phenoplast is itself a reaction product of the threecomponents resorcinol, m-aminophenol, and formaldehyde.
 3. Animprovement as claimed in claim 1, in which the phenoplast is aresorcinol-formaldehyde resin.
 4. An improvement as claimed in claim 3,in which the adhesive dip of resorcinol-formaldehyde resin and them-aminophenol dip are at least in part applied to the fibrous materialand dried thereon concurrently.
 5. An improvement as claimed in claim 3,in which the adhesive dip of resoRcinol-formaldehyde resin and them-aminophenol dip are at least in part applied to the fibrous materialand dried thereon sequentially.
 6. An improvement as claimed in claim 3,in which at least a part of the m-aminophenol dip is applied to thefibrous material after the drying thereon of the adhesive dip ofresorcinol-formaldehyde resin.
 7. An improvement as claimed in claim 3,wherein the fibrous material, on which the dips ofresorcinol-formaldehyde resin and of m-aminophenol are dried, comprisespolyamide fiber.
 8. An improvement as claimed in claim 3, wherein thefibrous material, on which the dips of resorcinol-formaldehyde resin andof m-aminophenol are dried, comprises glass fiber.
 9. An improvement asclaimed in claim 3, wherein the fibrous material, on which the dips ofresorcinol-formaldehyde resin and of m-aminophenol are dried, comprisesfibrous material which has been pretreated with an epoxy resin dip anddried.
 10. An improvement as claimed in claim 3, wherein the fibrousmaterial, on which the dips of resorcinol-formaldehyde resin and ofm-aminophenol are dried, comprises polyester fiber which has beenpretreated with an epoxy resin dip and dried.
 11. An improvement asclaimed in claim 3, wherein the fibrous material, on which the dips ofresorcinol-formaldehyde resin and of m-aminophenol are dried, comprisesglass fiber which has been pretreated with an epoxy resin dip and dried.12. An improvement as claimed in claim 3, in which theresorcinol-formaldehyde dip further comprises epoxy resin and is driedprior to applying the dip of m-aminophenol.
 13. An improvement asclaimed in claim 3, in which the adhesive dip of resorcinol-formaldehyderesin contains a proportion of elastomer latex.
 14. An improvement asclaimed in claim 13, in which the adhesive dip ofresorcinol-formaldehyde resin containing a proportion of elastomer latexand the m-aminophenol dip are at least in part applied to the fibrousmaterial and dried thereon concurrently.
 15. An improvement as claimedin claim 14, in which the adhesive dip of resorcinol-formaldehyde resincontaining a proportion of elastomer latex and the m-aminophenol dip areat least in part applied to the fibrous material and dried thereonsequentially.
 16. An improvement as claimed in claim 15, in which atleast a part of the m-aminophenol dip is applied to the fibrous materialafter the drying thereon of the adhesive dip of resorcinol-formaldehyderesin containing a proportion of elastomer latex.
 17. An improvement asclaimed in claim 13, wherein the fibrous material on which the dips ofresorcinol-formaldehyde resin containing a portion of elastomer latexand of m-aminophenol are dried, comprises polyamide fiber.
 18. Animprovement as claimed in claim 3, wherein the fibrous material, onwhich the dips of resorcinol-formaldehyde resin containing a proportionof elastomer latex and of m-aminophenol are dried, comprises glassfiber.
 19. An improvement as claimed in claim 3, wherein the fibrousmaterial, on which the dips of resorcinol-formaldehyde resin containinga proportion of elastomer latex and of m-aminophenol are dried,comprises fibrous material which has been pretreated with an epoxy resindip and dried.
 20. An improvement as claimed in claim 3, wherein thefibrous material, on which the dips of resorcinol-formaldehyde resincontaining a proportion of elastomer latex and of m-aminophenol aredried, comprises polyester fibers which has been pretreated with anepoxy resin dip and dried.
 21. An improvement as claimed in claim 13,wherein the fibrous material, on which the dips ofresorcinol-formaldehyde resin containing a proportion of elastomer latexand of m-aminophenol are dried, comprises glass fiber which has beenpretreated with an epoxy resin dip and dried.
 22. An improvement asclaimed in claim 13, in which the resorcinol-formaldehyde resin dipcontaining a proportion of elastomer latex further comprises epoxy resinand is dried prior to applying the dip of m-aminophenol.
 23. In theformation of a bond by vulcanizing a vulcanizable elastomer to a fibrousmaterial with the aid of a an adhesive dip of epoxy resin dried on thefibrous material before assembly with the elastomer and vulcanizationthereof, the improvement which comprises further applying to the fibrousmaterial, and drying thereon before such assembly, unresinifiedm-aminophenol.
 24. A composite structure consisting essentially of avulcanizable elastomer vulcanizate bonded to a fibrous material with theaid of a an adhesive or resorcinol-formaldehyde resin, particularlycharacterized in that the bonding of said adhesive is augmented byunresinified m-aminophenol applied to and dried on the fibrous materialprior to its assembly with the elastomer and vulcanization thereof. 25.A composite structure consisting essentially of a vulcanizable elastomervulcanizate bonded to a fibrous material with the aid of a an adhesiveof resorcinol-formaldehyde resin containing a proportion of elastomerlatex, particularly characterized in that the bonding of said adhesiveis augmented by resinified m-aminophenol applied to and dried on thefibrous material prior to its assembly with the elastomer andvulcanization thereof.
 26. A composite structure consisting essentiallyof a vulcanizable elastomer vulcanizate bonded to a fibrous materialwith the aid of (a) an epoxy resin adhesive and (b) an adhesive ofresorcinol-formaldehyde resin, particularly characterized in that thebonding of said adhesives is augmented by (c) resinified m-aminophenolapplied to and dried on the fibrous material prior to its assembly withthe elastomer and vulcanization thereof.
 27. A composite structureconsisting essentially of a vulcanizable elastomer vulcanizate bonded toa fibrous material with the aid of (a) an epoxy resin adhesive and (b)an adhesive of resorcinol-formaldehyde resin containing a proportion ofelastomer latex, particularly characterized in that the bonding of saidadhesives is augmented by (c) unresinified m-aminophenol applied to anddried on the fibrous material prior to its assembly with the elastomerand vulcanization thereof.